diff --git a/mozilla/accessible/src/base/nsAccessible.cpp b/mozilla/accessible/src/base/nsAccessible.cpp
index 9ac801e93d4..d7ae7390c95 100644
--- a/mozilla/accessible/src/base/nsAccessible.cpp
+++ b/mozilla/accessible/src/base/nsAccessible.cpp
@@ -740,7 +740,7 @@ void nsAccessible::GetBoundsRect(nsRect& aTotalBounds, nsIFrame** aBoundingFrame
       // Use next sibling if it exists, or go back up the tree to get the first next-in-flow or next-sibling 
       // within our search
       while (iterFrame) {
-        iterFrame->GetNextInFlow(&iterNextFrame);
+        iterNextFrame = iterFrame->GetNextInFlow();
         if (!iterNextFrame)
           iterNextFrame = iterFrame->GetNextSibling();
         if (iterNextFrame || --depth < 0) 
diff --git a/mozilla/content/base/src/nsDocumentViewer.cpp b/mozilla/content/base/src/nsDocumentViewer.cpp
index 37d82603967..19735fc2064 100644
--- a/mozilla/content/base/src/nsDocumentViewer.cpp
+++ b/mozilla/content/base/src/nsDocumentViewer.cpp
@@ -3203,7 +3203,7 @@ DocumentViewerImpl::PrintPreviewNavigate(PRInt16 aType, PRInt32 aPageNum)
 
   if (aType == nsIWebBrowserPrint::PRINTPREVIEW_PREV_PAGE) {
     if (currentPage) {
-      currentPage->GetPrevInFlow(&fndPageFrame);
+      fndPageFrame = currentPage->GetPrevInFlow();
       if (!fndPageFrame) {
         return NS_OK;
       }
@@ -3212,7 +3212,7 @@ DocumentViewerImpl::PrintPreviewNavigate(PRInt16 aType, PRInt32 aPageNum)
     }
   } else if (aType == nsIWebBrowserPrint::PRINTPREVIEW_NEXT_PAGE) {
     if (currentPage) {
-      currentPage->GetNextInFlow(&fndPageFrame);
+      fndPageFrame = currentPage->GetNextInFlow();
       if (!fndPageFrame) {
         return NS_OK;
       }
diff --git a/mozilla/content/base/src/nsSelection.cpp b/mozilla/content/base/src/nsSelection.cpp
index 0bbef348a1d..6d3560a4732 100644
--- a/mozilla/content/base/src/nsSelection.cpp
+++ b/mozilla/content/base/src/nsSelection.cpp
@@ -4839,7 +4839,8 @@ nsTypedSelection::selectFrames(nsPresContext* aPresContext,
         while (!frameRect.width || !frameRect.height)
         {
           //try to notify next in flow that its content is selected.
-          if (NS_SUCCEEDED(frame->GetNextInFlow(&frame)) && frame)
+          frame = frame->GetNextInFlow();
+          if (frame)
           {
             frameRect = frame->GetRect();
             frame->SetSelected(aPresContext, nsnull,aFlags,eSpreadDown);
diff --git a/mozilla/content/html/content/src/nsGenericHTMLElement.cpp b/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
index 33f002326fe..318ee4ab77a 100644
--- a/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
+++ b/mozilla/content/html/content/src/nsGenericHTMLElement.cpp
@@ -622,7 +622,7 @@ nsGenericHTMLElement::GetOffsetRect(nsRect& aRect, nsIContent** aOffsetParent)
 
   do {
     rcFrame.UnionRect(rcFrame, next->GetRect());
-    next->GetNextInFlow(&next);
+    next = next->GetNextInFlow();
   } while (next);
 
   if (rcFrame.IsEmpty()) {
diff --git a/mozilla/extensions/inspector/base/src/inFlasher.cpp b/mozilla/extensions/inspector/base/src/inFlasher.cpp
index c0d941a4734..636b2a08b0d 100644
--- a/mozilla/extensions/inspector/base/src/inFlasher.cpp
+++ b/mozilla/extensions/inspector/base/src/inFlasher.cpp
@@ -188,7 +188,7 @@ inFlasher::DrawElementOutline(nsIDOMElement* aElement)
       rcontext->InvertRect(rect);
     }
 
-    frame->GetNextInFlow(&frame);
+    frame = frame->GetNextInFlow();
 
     PRBool isLastFrame = (frame == nsnull);
     DrawOutline(rect.x, rect.y, rect.width, rect.height, p2t, rcontext,
diff --git a/mozilla/extensions/typeaheadfind/src/nsTypeAheadFind.cpp b/mozilla/extensions/typeaheadfind/src/nsTypeAheadFind.cpp
index 82cea75fe88..28c3694ff45 100644
--- a/mozilla/extensions/typeaheadfind/src/nsTypeAheadFind.cpp
+++ b/mozilla/extensions/typeaheadfind/src/nsTypeAheadFind.cpp
@@ -2574,8 +2574,7 @@ nsTypeAheadFind::IsRangeVisible(nsIPresShell *aPresShell,
     if (startRangeOffset < endFrameOffset) {
       break;
     }
-    nsIFrame *nextInFlowFrame = nsnull;
-    frame->GetNextInFlow(&nextInFlowFrame);
+    nsIFrame *nextInFlowFrame = frame->GetNextInFlow();
     if (nextInFlowFrame) {
       frame = nextInFlowFrame;
     }
diff --git a/mozilla/layout/base/nsBidiPresUtils.cpp b/mozilla/layout/base/nsBidiPresUtils.cpp
index 6d216f093a5..03544d26e05 100644
--- a/mozilla/layout/base/nsBidiPresUtils.cpp
+++ b/mozilla/layout/base/nsBidiPresUtils.cpp
@@ -803,7 +803,7 @@ nsBidiPresUtils::RemoveBidiContinuation(nsPresContext* aPresContext,
     frame = aFrame;
     do {
       propTable->DeleteProperty(frame, nsLayoutAtoms::nextBidi);
-      frame->GetPrevInFlow(&frame);
+      frame = frame->GetPrevInFlow();
       if (!frame) {
         break;
       }
diff --git a/mozilla/layout/base/nsCSSFrameConstructor.cpp b/mozilla/layout/base/nsCSSFrameConstructor.cpp
index 255c49c8612..82a7615f02f 100644
--- a/mozilla/layout/base/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/base/nsCSSFrameConstructor.cpp
@@ -450,8 +450,7 @@ GetLastSpecialSibling(nsFrameManager* aFrameManager, nsIFrame* aFrame)
 static nsIFrame*
 GetNifOrSpecialSibling(nsFrameManager *aFrameManager, nsIFrame *aFrame)
 {
-  nsIFrame *result;
-  aFrame->GetNextInFlow(&result);
+  nsIFrame *result = aFrame->GetNextInFlow();
   if (result)
     return result;
 
@@ -466,17 +465,14 @@ SetFrameIsSpecial(nsFrameManager* aFrameManager, nsIFrame* aFrame, nsIFrame* aSp
   NS_PRECONDITION(aFrameManager && aFrame, "bad args!");
 
   // Mark the frame and all of its siblings as "special".
-  for (nsIFrame* frame = aFrame; frame != nsnull; frame->GetNextInFlow(&frame)) {
+  for (nsIFrame* frame = aFrame; frame != nsnull; frame = frame->GetNextInFlow()) {
     frame->AddStateBits(NS_FRAME_IS_SPECIAL);
   }
 
   if (aSpecialSibling) {
-#ifdef DEBUG
     // We should be the first-in-flow
-    nsIFrame* prev;
-    aFrame->GetPrevInFlow(&prev);
-    NS_ASSERTION(! prev, "assigning special sibling to other than first-in-flow!");
-#endif
+    NS_ASSERTION(!aFrame->GetPrevInFlow(),
+                 "assigning special sibling to other than first-in-flow!");
 
     // Store the "special sibling" (if we were given one) with the
     // first frame in the flow.
@@ -7810,12 +7806,9 @@ FindNextAnonymousSibling(nsIPresShell* aPresShell,
     nsIFrame* nextSibling;
     aPresShell->GetPrimaryFrameFor(child, &nextSibling);
     if (nextSibling) {
-#ifdef DEBUG
       // The primary frame should never be a continuation
-      nsIFrame* prevInFlow;
-      nextSibling->GetPrevInFlow(&prevInFlow);
-      NS_ASSERTION(!prevInFlow, "primary frame is a continuation!?");
-#endif
+      NS_ASSERTION(!nextSibling->GetPrevInFlow(),
+                   "primary frame is a continuation!?");
 
       // If the frame is out-of-flow, GPFF() will have returned the
       // out-of-flow frame; we want the placeholder.
@@ -7996,12 +7989,9 @@ nsCSSFrameConstructor::FindNextSibling(nsIPresShell*     aPresShell,
     aPresShell->GetPrimaryFrameFor(nsCOMPtr<nsIContent>(*iter), &nextSibling);
 
     if (nextSibling) {
-#ifdef DEBUG
       // The frame primary frame should never be a continuation
-      nsIFrame* prevInFlow;
-      nextSibling->GetPrevInFlow(&prevInFlow);
-      NS_ASSERTION(!prevInFlow, "primary frame is a continuation!?");
-#endif
+      NS_ASSERTION(!nextSibling->GetPrevInFlow(),
+                   "primary frame is a continuation!?");
 
       // If the frame is out-of-flow, GPFF() will have returned the
       // out-of-flow frame; we want the placeholder.
@@ -9298,7 +9288,7 @@ DeletingFrameSubtree(nsPresContext*  aPresContext,
       // recursing over a subtree, because those continuing frames should be
       // found as part of the walk over the top-most frame's continuing frames.
       // Walking them again will make this an N^2/2 algorithm
-      aFrame->GetNextInFlow(&aFrame);
+      aFrame = aFrame->GetNextInFlow();
     } while (aFrame);
 
     // Now destroy any frames that have been enqueued for destruction.
@@ -10691,8 +10681,7 @@ nsCSSFrameConstructor::CreateContinuingTableFrame(nsIPresShell* aPresShell,
       if ((NS_STYLE_DISPLAY_TABLE_HEADER_GROUP == display->mDisplay) ||
           (NS_STYLE_DISPLAY_TABLE_FOOTER_GROUP == display->mDisplay)) {
         // If the row group has was continued, then don't replicate it
-        nsIFrame* rgNextInFlow;
-        rowGroupFrame->GetNextInFlow(&rgNextInFlow);
+        nsIFrame* rgNextInFlow = rowGroupFrame->GetNextInFlow();
         if (rgNextInFlow) {
           ((nsTableRowGroupFrame*)rowGroupFrame)->SetRepeatable(PR_FALSE);
         }
@@ -10746,9 +10735,7 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsPresContext* aPresContext,
   nsStyleContext*            styleContext = aFrame->GetStyleContext();
   nsIFrame*                  newFrame = nsnull;
   nsresult                   rv = NS_OK;
-  nsIFrame*                  nextInFlow = nsnull;
-
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame*                  nextInFlow = aFrame->GetNextInFlow();
 
   // Use the frame type to determine what type of frame to create
   nsIAtom* frameType = aFrame->GetType();
@@ -10944,8 +10931,7 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsPresContext* aPresContext,
     return NS_ERROR_UNEXPECTED;
   }
 
-  nsIFrame* prevPage;
-  pageFrame->GetPrevInFlow(&prevPage);
+  nsIFrame* prevPage = pageFrame->GetPrevInFlow();
   if (!prevPage) {
     return NS_OK;
   }
@@ -11877,8 +11863,7 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
         // need to be pulled out of the line-frame and become children
         // of the block.
         nsIFrame* nextSibling = aPrevSibling->GetNextSibling();
-        nsIFrame* nextLineFrame;
-        prevSiblingParent->GetNextInFlow(&nextLineFrame);
+        nsIFrame* nextLineFrame = prevSiblingParent->GetNextInFlow();
         if (nextSibling || nextLineFrame) {
           // Oy. We have work to do. Create a list of the new frames
           // that are going into the block by stripping them away from
@@ -11891,7 +11876,7 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
 
           nsLineFrame* nextLineFrame = (nsLineFrame*) lineFrame;
           for (;;) {
-            nextLineFrame->GetNextInFlow(&nextLineFrame);
+            nextLineFrame = nextLineFrame->GetNextInFlow();
             if (!nextLineFrame) {
               break;
             }
@@ -12324,8 +12309,7 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
 
   // Destroy the old text frame's continuations (the old text frame
   // will be destroyed when its letter frame is destroyed).
-  nsIFrame* nextTextFrame;
-  textFrame->GetNextInFlow(&nextTextFrame);
+  nsIFrame* nextTextFrame = textFrame->GetNextInFlow();
   if (nextTextFrame) {
     nsIFrame* nextTextParent = nextTextFrame->GetParent();
     if (nextTextParent) {
@@ -13268,8 +13252,7 @@ nsCSSFrameConstructor::SplitToContainingBlock(nsPresContext* aPresContext,
 
   // If we have a continuation frame, then we need to break the
   // continuation.
-  nsIFrame* nextInFlow;
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aFrame->GetNextInFlow();
   if (nextInFlow) {
     aFrame->SetNextInFlow(nsnull);
     nextInFlow->SetPrevInFlow(nsnull);
diff --git a/mozilla/layout/base/nsCSSRendering.cpp b/mozilla/layout/base/nsCSSRendering.cpp
index eeae52f1fc9..60ff6f6bd12 100644
--- a/mozilla/layout/base/nsCSSRendering.cpp
+++ b/mozilla/layout/base/nsCSSRendering.cpp
@@ -145,8 +145,7 @@ protected:
   {
     NS_PRECONDITION(aFrame, "Need a frame");
 
-    nsIFrame *prevInFlow = nsnull;
-    aFrame->GetPrevInFlow(&prevInFlow);
+    nsIFrame *prevInFlow = aFrame->GetPrevInFlow();
 
     if (!prevInFlow || mFrame != prevInFlow) {
       // Ok, we've got the wrong frame.  We have to start from scratch.
@@ -163,18 +162,17 @@ protected:
   }
 
   void Init(nsIFrame* aFrame)
-  {
-    nsIFrame* inlineFrame;
+  {    
     // Start with the previous flow frame as our continuation point
     // is the total of the widths of the previous frames.
-    aFrame->GetPrevInFlow(&inlineFrame);
+    nsIFrame* inlineFrame = aFrame->GetPrevInFlow();
 
     while (inlineFrame) {
       nsRect rect = inlineFrame->GetRect();
       mContinuationPoint += rect.width;
       mUnbrokenWidth += rect.width;
       mBoundingBox.UnionRect(mBoundingBox, rect);
-      inlineFrame->GetPrevInFlow(&inlineFrame);
+      inlineFrame = inlineFrame->GetPrevInFlow();
     }
 
     // Next add this frame and subsequent frames to the bounding box and
@@ -184,7 +182,7 @@ protected:
       nsRect rect = inlineFrame->GetRect();
       mUnbrokenWidth += rect.width;
       mBoundingBox.UnionRect(mBoundingBox, rect);
-      inlineFrame->GetNextInFlow(&inlineFrame);
+      inlineFrame = inlineFrame->GetNextInFlow();
     }
 
     mFrame = aFrame;
diff --git a/mozilla/layout/base/nsDocumentViewer.cpp b/mozilla/layout/base/nsDocumentViewer.cpp
index 37d82603967..19735fc2064 100644
--- a/mozilla/layout/base/nsDocumentViewer.cpp
+++ b/mozilla/layout/base/nsDocumentViewer.cpp
@@ -3203,7 +3203,7 @@ DocumentViewerImpl::PrintPreviewNavigate(PRInt16 aType, PRInt32 aPageNum)
 
   if (aType == nsIWebBrowserPrint::PRINTPREVIEW_PREV_PAGE) {
     if (currentPage) {
-      currentPage->GetPrevInFlow(&fndPageFrame);
+      fndPageFrame = currentPage->GetPrevInFlow();
       if (!fndPageFrame) {
         return NS_OK;
       }
@@ -3212,7 +3212,7 @@ DocumentViewerImpl::PrintPreviewNavigate(PRInt16 aType, PRInt32 aPageNum)
     }
   } else if (aType == nsIWebBrowserPrint::PRINTPREVIEW_NEXT_PAGE) {
     if (currentPage) {
-      currentPage->GetNextInFlow(&fndPageFrame);
+      fndPageFrame = currentPage->GetNextInFlow();
       if (!fndPageFrame) {
         return NS_OK;
       }
diff --git a/mozilla/layout/base/nsFrameContentIterator.cpp b/mozilla/layout/base/nsFrameContentIterator.cpp
index 31e0f8c46bd..18419911c87 100644
--- a/mozilla/layout/base/nsFrameContentIterator.cpp
+++ b/mozilla/layout/base/nsFrameContentIterator.cpp
@@ -122,8 +122,7 @@ GetNextChildFrame(nsPresContext* aPresContext, nsIFrame* aFrame)
   // If there's no next sibling, then check if the parent frame
   // has a next-in-flow and look there
   if (!nextSibling) {
-    nsIFrame* parent;
-    aFrame->GetParent()->GetNextInFlow(&parent);
+    nsIFrame* parent = aFrame->GetParent()->GetNextInFlow();
 
     if (parent) {
       nextSibling = parent->GetFirstChild(nsnull);
@@ -184,7 +183,7 @@ GetPrevChildFrame(nsPresContext* aPresContext, nsIFrame* aFrame)
   // If there's no previous sibling, then check if the parent frame
   // has a prev-in-flow and look there
   if (!prevSibling) {
-    parent->GetPrevInFlow(&parent);
+    parent = parent->GetPrevInFlow();
 
     if (parent) {
       firstChild = parent->GetFirstChild(nsnull);
@@ -195,8 +194,7 @@ GetPrevChildFrame(nsPresContext* aPresContext, nsIFrame* aFrame)
   
   // Get the first-in-flow
   while (PR_TRUE) {
-    nsIFrame* prevInFlow;
-    prevSibling->GetPrevInFlow(&prevInFlow);
+    nsIFrame* prevInFlow = prevSibling->GetPrevInFlow();
     if (prevInFlow) {
       prevSibling = prevInFlow;
     } else {
diff --git a/mozilla/layout/base/nsFrameManager.cpp b/mozilla/layout/base/nsFrameManager.cpp
index 205e4111135..99933fe8e36 100644
--- a/mozilla/layout/base/nsFrameManager.cpp
+++ b/mozilla/layout/base/nsFrameManager.cpp
@@ -1498,8 +1498,7 @@ nsFrameManager::ReResolveStyleContext(nsPresContext    *aPresContext,
           localContent->IsContentOfType(nsIContent::eELEMENT)) {
         // Check for a new :before pseudo and an existing :before
         // frame, but only if the frame is the first-in-flow.
-        nsIFrame* prevInFlow = nsnull;
-        aFrame->GetPrevInFlow(&prevInFlow);
+        nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
         if (!prevInFlow) {
           // Checking for a :before frame is cheaper than getting the
           // :before style context.
@@ -1524,8 +1523,7 @@ nsFrameManager::ReResolveStyleContext(nsPresContext    *aPresContext,
           localContent->IsContentOfType(nsIContent::eELEMENT)) {
         // Check for new :after content, but only if the frame is the
         // first-in-flow.
-        nsIFrame* nextInFlow = nsnull;
-        aFrame->GetNextInFlow(&nextInFlow);
+        nsIFrame* nextInFlow = aFrame->GetNextInFlow();
 
         if (!nextInFlow) {
           // Getting the :after frame is more expensive than getting the pseudo
@@ -1623,13 +1621,7 @@ nsFrameManager::ComputeStyleChangeFor(nsIFrame          *aFrame,
   nsIFrame* frame = aFrame;
   nsIFrame* frame2 = aFrame;
 
-#ifdef DEBUG
-  {
-    nsIFrame* prevInFlow;
-    frame->GetPrevInFlow(&prevInFlow);
-    NS_ASSERTION(!prevInFlow, "must start with the first in flow");
-  }
-#endif
+  NS_ASSERTION(!frame->GetPrevInFlow(), "must start with the first in flow");
 
   // We want to start with this frame and walk all its next-in-flows,
   // as well as all its special siblings and their next-in-flows,
@@ -1650,15 +1642,12 @@ nsFrameManager::ComputeStyleChangeFor(nsIFrame          *aFrame,
         // If it's going to cause a framechange, then don't bother
         // with the continuations or special siblings since they'll be
         // clobbered by the frame reconstruct anyway.
-#ifdef NS_DEBUG
-        nsIFrame* prevInFlow;
-        frame->GetPrevInFlow(&prevInFlow);
-        NS_ASSERTION(!prevInFlow, "continuing frame had more severe impact than first-in-flow");
-#endif
+        NS_ASSERTION(!frame->GetPrevInFlow(),
+                     "continuing frame had more severe impact than first-in-flow");
         return topLevelChange;
       }
 
-      frame->GetNextInFlow(&frame);
+      frame = frame->GetNextInFlow();
     } while (frame);
 
     // Might we have special siblings?
diff --git a/mozilla/layout/base/nsLayoutUtils.cpp b/mozilla/layout/base/nsLayoutUtils.cpp
index 247f65d4288..69e449d78f8 100644
--- a/mozilla/layout/base/nsLayoutUtils.cpp
+++ b/mozilla/layout/base/nsLayoutUtils.cpp
@@ -131,11 +131,7 @@ nsIFrame*
 nsLayoutUtils::GetBeforeFrame(nsIFrame* aFrame, nsPresContext* aPresContext)
 {
   NS_PRECONDITION(aFrame, "NULL frame pointer");
-#ifdef DEBUG
-  nsIFrame* prevInFlow = nsnull;
-  aFrame->GetPrevInFlow(&prevInFlow);
-  NS_ASSERTION(!prevInFlow, "aFrame must be first-in-flow");
-#endif
+  NS_ASSERTION(!aFrame->GetPrevInFlow(), "aFrame must be first-in-flow");
   
   nsIFrame* firstFrame = GetFirstChildFrame(aPresContext, aFrame, aFrame->GetContent());
 
diff --git a/mozilla/layout/base/public/nsIFrame.h b/mozilla/layout/base/public/nsIFrame.h
index b8268bc076e..baee4f7ba37 100644
--- a/mozilla/layout/base/public/nsIFrame.h
+++ b/mozilla/layout/base/public/nsIFrame.h
@@ -825,9 +825,9 @@ public:
   /**
    * Flow member functions
    */
-  NS_IMETHOD  GetPrevInFlow(nsIFrame** aPrevInFlow) const = 0;
+  virtual nsIFrame* GetPrevInFlow() const = 0;
   NS_IMETHOD  SetPrevInFlow(nsIFrame*) = 0;
-  NS_IMETHOD  GetNextInFlow(nsIFrame** aNextInFlow) const = 0;
+  virtual nsIFrame* GetNextInFlow() const = 0;
   NS_IMETHOD  SetNextInFlow(nsIFrame*) = 0;
 
   /**
diff --git a/mozilla/layout/base/src/nsBidiPresUtils.cpp b/mozilla/layout/base/src/nsBidiPresUtils.cpp
index 6d216f093a5..03544d26e05 100644
--- a/mozilla/layout/base/src/nsBidiPresUtils.cpp
+++ b/mozilla/layout/base/src/nsBidiPresUtils.cpp
@@ -803,7 +803,7 @@ nsBidiPresUtils::RemoveBidiContinuation(nsPresContext* aPresContext,
     frame = aFrame;
     do {
       propTable->DeleteProperty(frame, nsLayoutAtoms::nextBidi);
-      frame->GetPrevInFlow(&frame);
+      frame = frame->GetPrevInFlow();
       if (!frame) {
         break;
       }
diff --git a/mozilla/layout/base/src/nsLayoutUtils.cpp b/mozilla/layout/base/src/nsLayoutUtils.cpp
index 247f65d4288..69e449d78f8 100644
--- a/mozilla/layout/base/src/nsLayoutUtils.cpp
+++ b/mozilla/layout/base/src/nsLayoutUtils.cpp
@@ -131,11 +131,7 @@ nsIFrame*
 nsLayoutUtils::GetBeforeFrame(nsIFrame* aFrame, nsPresContext* aPresContext)
 {
   NS_PRECONDITION(aFrame, "NULL frame pointer");
-#ifdef DEBUG
-  nsIFrame* prevInFlow = nsnull;
-  aFrame->GetPrevInFlow(&prevInFlow);
-  NS_ASSERTION(!prevInFlow, "aFrame must be first-in-flow");
-#endif
+  NS_ASSERTION(!aFrame->GetPrevInFlow(), "aFrame must be first-in-flow");
   
   nsIFrame* firstFrame = GetFirstChildFrame(aPresContext, aFrame, aFrame->GetContent());
 
diff --git a/mozilla/layout/generic/nsBlockFrame.cpp b/mozilla/layout/generic/nsBlockFrame.cpp
index eb78a3b9704..91c7e167f49 100644
--- a/mozilla/layout/generic/nsBlockFrame.cpp
+++ b/mozilla/layout/generic/nsBlockFrame.cpp
@@ -827,8 +827,7 @@ nsBlockFrame::Reflow(nsPresContext*          aPresContext,
   NS_ASSERTION(NS_SUCCEEDED(rv), "reflow dirty lines failed");
   if (NS_FAILED(rv)) return rv;
 
-  nsIFrame* nextInFlow;
-  GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = GetNextInFlow();
   if (nextInFlow && NS_FRAME_IS_NOT_COMPLETE(state.mReflowStatus)) {
     if (GetOverflowLines() || GetOverflowPlaceholders()) {
       state.mReflowStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
@@ -1243,7 +1242,7 @@ nsBlockFrame::ComputeFinalSize(const nsHTMLReflowState& aReflowState,
       if (mPrevInFlow) {
         // Reduce the height by the height of prev-in-flows. The last-in-flow will automatically
         // pick up the bottom border/padding, since it was part of the original aMetrics.height.
-        for (nsIFrame* prev = mPrevInFlow; prev; prev->GetPrevInFlow(&prev)) {
+        for (nsIFrame* prev = mPrevInFlow; prev; prev = prev->GetPrevInFlow()) {
           aMetrics.height -= prev->GetRect().height;
           // XXX: All block level next-in-flows have borderPadding.top applied to them (bug 174688). 
           // The following should be removed when this gets fixed. bug 174688 prevents us from honoring 
@@ -1461,8 +1460,7 @@ nsBlockFrame::PrepareChildIncrementalReflow(nsBlockReflowState& aState)
         // of the continuations. This will allow the incremental
         // reflow to arrive at the target frame during the first-pass
         // unconstrained reflow.
-        nsIFrame *prevInFlow;
-        (*iter)->GetPrevInFlow(&prevInFlow);
+        nsIFrame *prevInFlow = (*iter)->GetPrevInFlow();
         if (prevInFlow)
           RetargetInlineIncrementalReflow(iter, line, prevInFlow);
       }
@@ -1507,7 +1505,7 @@ nsBlockFrame::RetargetInlineIncrementalReflow(nsReflowPath::iterator &aTarget,
       break;
 
     *aTarget = aPrevInFlow;
-    aPrevInFlow->GetPrevInFlow(&aPrevInFlow);
+    aPrevInFlow = aPrevInFlow->GetPrevInFlow();
 
 #ifdef DEBUG
     // Paranoia. Ensure that the prev-in-flow is really in the
@@ -1548,7 +1546,7 @@ nsBlockFrame::RetargetInlineIncrementalReflow(nsReflowPath::iterator &aTarget,
       PRInt32 count = lineCount;
       nsIFrame *prevInFlow;
       do {
-        frame->GetPrevInFlow(&prevInFlow);
+        prevInFlow = frame->GetPrevInFlow();
       } while (--count >= 0 && prevInFlow && (frame = prevInFlow));
 
       path->ReplaceElementAt(frame, i);
@@ -2975,8 +2973,7 @@ nsBlockFrame::ReflowBlockFrame(nsBlockReflowState& aState,
   // apply its top margin because its not significant. Otherwise, dig
   // deeper.
   PRBool applyTopMargin = PR_FALSE;
-  nsIFrame* framePrevInFlow;
-  frame->GetPrevInFlow(&framePrevInFlow);
+  nsIFrame* framePrevInFlow = frame->GetPrevInFlow();
   if (nsnull == framePrevInFlow) {
     applyTopMargin = ShouldApplyTopMargin(aState, aLine);
   }
@@ -4746,8 +4743,7 @@ nsBlockFrame::DoRemoveOutOfFlowFrame(nsPresContext* aPresContext,
                                      nsIFrame*       aFrame)
 {
   // First remove aFrame's next in flow
-  nsIFrame* nextInFlow;
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aFrame->GetNextInFlow();
   if (nextInFlow) {
     nsBlockFrame::DoRemoveOutOfFlowFrame(aPresContext, nextInFlow);
   }
@@ -4890,8 +4886,7 @@ nsBlockFrame::DoRemoveFrame(nsPresContext* aPresContext,
 
       // Destroy frame; capture its next-in-flow first in case we need
       // to destroy that too.
-      nsIFrame* nextInFlow;
-      aDeletedFrame->GetNextInFlow(&nextInFlow);
+      nsIFrame* nextInFlow = aDeletedFrame->GetNextInFlow();
 #ifdef NOISY_REMOVE_FRAME
       printf("DoRemoveFrame: line=%p frame=", line);
       nsFrame::ListTag(stdout, aDeletedFrame);
@@ -4973,8 +4968,7 @@ void
 nsBlockFrame::DeleteNextInFlowChild(nsPresContext* aPresContext,
                                     nsIFrame*       aNextInFlow)
 {
-  nsIFrame* prevInFlow;
-  aNextInFlow->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aNextInFlow->GetPrevInFlow();
   NS_PRECONDITION(prevInFlow, "bad next-in-flow");
   NS_PRECONDITION(IsChild(aNextInFlow), "bad geometric parent");
 
@@ -4997,8 +4991,7 @@ nsBlockFrame::ReflowFloat(nsBlockReflowState& aState,
                           nsReflowStatus&     aReflowStatus)
 {
   // Delete the placeholder's next in flows, if any
-  nsIFrame* nextInFlow;
-  aPlaceholder->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aPlaceholder->GetNextInFlow();
   if (nextInFlow) {
     // If aPlaceholder's parent is an inline, nextInFlow's will be a block.
     NS_STATIC_CAST(nsHTMLContainerFrame*, nextInFlow->GetParent())
@@ -5025,8 +5018,7 @@ nsBlockFrame::ReflowFloat(nsBlockReflowState& aState,
   else {
     const nsStyleDisplay* floatDisplay = floatFrame->GetStyleDisplay();
 
-    nsIFrame* prevInFlow;
-    floatFrame->GetPrevInFlow(&prevInFlow);
+    nsIFrame* prevInFlow = floatFrame->GetPrevInFlow();
     // if the float is continued, constrain its width to the prev-in-flow's width
     if (prevInFlow) {
       availWidth = prevInFlow->GetRect().width;
@@ -5168,8 +5160,7 @@ nsBlockFrame::ReflowFloat(nsBlockReflowState& aState,
   // If the placeholder was continued and its first-in-flow was followed by a 
   // <BR>, then cache the <BR>'s break type in aState.mFloatBreakType so that
   // the next frame after the placeholder can combine that break type with its own
-  nsIFrame* prevPlaceholder = nsnull;
-  aPlaceholder->GetPrevInFlow(&prevPlaceholder);
+  nsIFrame* prevPlaceholder = aPlaceholder->GetPrevInFlow();
   if (prevPlaceholder) {
     // the break occurs only after the last continued placeholder
     PRBool lastPlaceholder = PR_TRUE;
@@ -6155,8 +6146,7 @@ nsBlockFrame::IsChild(nsIFrame* aFrame)
   // and placeholders don't satisfy InSiblingList().  
   PRBool skipLineList    = PR_FALSE;
   PRBool skipSiblingList = PR_FALSE;
-  nsIFrame* prevInFlow;
-  aFrame->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
   if (prevInFlow) {
     nsFrameState state = aFrame->GetStateBits();
     skipLineList    = (state & NS_FRAME_OUT_OF_FLOW); 
@@ -6359,7 +6349,7 @@ nsBlockFrame::RenumberListsInBlock(nsPresContext* aPresContext,
     }
 
     // Advance to the next continuation
-    aBlockFrame->GetNextInFlow((nsIFrame**) &aBlockFrame);
+    aBlockFrame = NS_STATIC_CAST(nsBlockFrame*, aBlockFrame->GetNextInFlow());
   }
 
   return renumberedABullet;
diff --git a/mozilla/layout/generic/nsBlockReflowContext.cpp b/mozilla/layout/generic/nsBlockReflowContext.cpp
index 1117e1c2fae..021b9a25b6a 100644
--- a/mozilla/layout/generic/nsBlockReflowContext.cpp
+++ b/mozilla/layout/generic/nsBlockReflowContext.cpp
@@ -617,8 +617,7 @@ nsBlockReflowContext::ReflowBlock(const nsRect&       aSpace,
     // the frame is going to get reflowed again (and may end up wanting
     // a next-in-flow where it ends up), unless it is an out of flow frame.
     if (NS_FRAME_IS_COMPLETE(aFrameReflowStatus)) {
-      nsIFrame* kidNextInFlow;
-      mFrame->GetNextInFlow(&kidNextInFlow);
+      nsIFrame* kidNextInFlow = mFrame->GetNextInFlow();
       if (nsnull != kidNextInFlow) {
         // Remove all of the childs next-in-flows. Make sure that we ask
         // the right parent to do the removal (it's possible that the
diff --git a/mozilla/layout/generic/nsBlockReflowState.cpp b/mozilla/layout/generic/nsBlockReflowState.cpp
index c644b5d9a86..0a3accdb217 100644
--- a/mozilla/layout/generic/nsBlockReflowState.cpp
+++ b/mozilla/layout/generic/nsBlockReflowState.cpp
@@ -99,7 +99,7 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
   mReflowStatus = NS_FRAME_COMPLETE;
 
   mPresContext = aPresContext;
-  mBlock->GetNextInFlow(NS_REINTERPRET_CAST(nsIFrame**, &mNextInFlow));
+  mNextInFlow = NS_STATIC_CAST(nsBlockFrame*, mBlock->GetNextInFlow());
   mKidXMost = 0;
 
   // Compute content area width (the content area is inside the border
@@ -953,17 +953,15 @@ nsBlockReflowState::FlowAndPlaceFloat(nsFloatCache*   aFloatCache,
   }
   // If the float is continued, it will get the same absolute x value as its prev-in-flow
   nsRect prevRect(0,0,0,0);
-  nsIFrame* prevInFlow;
-  floatFrame->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = floatFrame->GetPrevInFlow();
   if (prevInFlow) {
     prevRect = prevInFlow->GetRect();
 
-    nsIFrame *placeParentPrev, *prevPlace;
     // If prevInFlow's placeholder is in a block that wasn't continued, we need to adjust 
     // prevRect.x to account for the missing frame offsets.
     nsIFrame* placeParent = placeholder->GetParent();
-    placeParent->GetPrevInFlow(&placeParentPrev);
-    prevPlace =
+    nsIFrame* placeParentPrev = placeParent->GetPrevInFlow();
+    nsIFrame* prevPlace =
       mPresContext->FrameManager()->GetPlaceholderFrameFor(prevInFlow);
 
     nsIFrame* prevPlaceParent = prevPlace->GetParent();
diff --git a/mozilla/layout/generic/nsContainerFrame.cpp b/mozilla/layout/generic/nsContainerFrame.cpp
index 0ce9fd3b615..e065b06d262 100644
--- a/mozilla/layout/generic/nsContainerFrame.cpp
+++ b/mozilla/layout/generic/nsContainerFrame.cpp
@@ -991,8 +991,7 @@ nsContainerFrame::ReflowChild(nsIFrame*                aKidFrame,
   // If the reflow was successful and the child frame is complete, delete any
   // next-in-flows
   if (NS_SUCCEEDED(result) && NS_FRAME_IS_COMPLETE(aStatus)) {
-    nsIFrame* kidNextInFlow;
-    aKidFrame->GetNextInFlow(&kidNextInFlow);
+    nsIFrame* kidNextInFlow = aKidFrame->GetNextInFlow();
     if (nsnull != kidNextInFlow) {
       // Remove all of the childs next-in-flows. Make sure that we ask
       // the right parent to do the removal (it's possible that the
@@ -1107,15 +1106,13 @@ void
 nsContainerFrame::DeleteNextInFlowChild(nsPresContext* aPresContext,
                                         nsIFrame*       aNextInFlow)
 {
-  nsIFrame* prevInFlow;
-  aNextInFlow->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aNextInFlow->GetPrevInFlow();
   NS_PRECONDITION(prevInFlow, "bad prev-in-flow");
   NS_PRECONDITION(mFrames.ContainsFrame(aNextInFlow), "bad geometric parent");
 
   // If the next-in-flow has a next-in-flow then delete it, too (and
   // delete it first).
-  nsIFrame* nextNextInFlow;
-  aNextInFlow->GetNextInFlow(&nextNextInFlow);
+  nsIFrame* nextNextInFlow = aNextInFlow->GetNextInFlow();
   if (nextNextInFlow) {
     NS_STATIC_CAST(nsContainerFrame*, nextNextInFlow->GetParent())
       ->DeleteNextInFlowChild(aPresContext, nextNextInFlow);
@@ -1153,11 +1150,7 @@ nsContainerFrame::DeleteNextInFlowChild(nsPresContext* aPresContext,
   // Delete the next-in-flow frame and its descendants.
   aNextInFlow->Destroy(aPresContext);
 
-#ifdef NS_DEBUG
-  nsIFrame* nextInFlow;
-  prevInFlow->GetNextInFlow(&nextInFlow);
-  NS_POSTCONDITION(!nextInFlow, "non null next-in-flow");
-#endif
+  NS_POSTCONDITION(!prevInFlow->GetNextInFlow(), "non null next-in-flow");
 }
 
 nsIFrame*
diff --git a/mozilla/layout/generic/nsFirstLetterFrame.cpp b/mozilla/layout/generic/nsFirstLetterFrame.cpp
index 3cbf8c847ac..11a672dce8e 100644
--- a/mozilla/layout/generic/nsFirstLetterFrame.cpp
+++ b/mozilla/layout/generic/nsFirstLetterFrame.cpp
@@ -292,8 +292,7 @@ nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
   // Create a continuation or remove existing continuations based on
   // the reflow completion status.
   if (NS_FRAME_IS_COMPLETE(aReflowStatus)) {
-    nsIFrame* kidNextInFlow;
-    kid->GetNextInFlow(&kidNextInFlow);
+    nsIFrame* kidNextInFlow = kid->GetNextInFlow();
     if (kidNextInFlow) {
       // Remove all of the childs next-in-flows
       NS_STATIC_CAST(nsContainerFrame*, kidNextInFlow->GetParent())
diff --git a/mozilla/layout/generic/nsFrame.cpp b/mozilla/layout/generic/nsFrame.cpp
index a50cbdd7021..2d0501504bb 100644
--- a/mozilla/layout/generic/nsFrame.cpp
+++ b/mozilla/layout/generic/nsFrame.cpp
@@ -1221,9 +1221,8 @@ ContentContainsPoint(nsPresContext *aPresContext,
       return PR_TRUE;
     }
 
-    rv = frame->GetNextInFlow(&frame);
+    frame = frame->GetNextInFlow();
 
-    if (NS_FAILED(rv)) return PR_FALSE;
   }
 
   return PR_FALSE;
@@ -2100,8 +2099,7 @@ nsFrame::DidReflow(nsPresContext*           aPresContext,
       aReflowState->mStylePosition                                     && // percent height
       (eStyleUnit_Percent == aReflowState->mStylePosition->mHeight.GetUnit())) {
 
-    nsIFrame* prevInFlow;
-    GetPrevInFlow(&prevInFlow);
+    nsIFrame* prevInFlow = GetPrevInFlow();
     if (!prevInFlow) { // 1st in flow
       aReflowState->mPercentHeightObserver->NotifyPercentHeight(*aReflowState);
     }
@@ -2181,10 +2179,9 @@ NS_IMETHODIMP nsFrame::IsSplittable(nsSplittableType& aIsSplittable) const
   return NS_OK;
 }
 
-NS_IMETHODIMP nsFrame::GetPrevInFlow(nsIFrame** aPrevInFlow) const
+nsIFrame* nsFrame::GetPrevInFlow() const
 {
-  *aPrevInFlow = nsnull;
-  return NS_OK;
+  return nsnull;
 }
 
 NS_IMETHODIMP nsFrame::SetPrevInFlow(nsIFrame* aPrevInFlow)
@@ -2198,10 +2195,9 @@ NS_IMETHODIMP nsFrame::SetPrevInFlow(nsIFrame* aPrevInFlow)
   return NS_OK;
 }
 
-NS_IMETHODIMP nsFrame::GetNextInFlow(nsIFrame** aNextInFlow) const
+nsIFrame* nsFrame::GetNextInFlow() const
 {
-  *aNextInFlow = nsnull;
-  return NS_OK;
+  return nsnull;
 }
 
 NS_IMETHODIMP nsFrame::SetNextInFlow(nsIFrame*)
@@ -3042,10 +3038,10 @@ nsFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset, PRBool inHint, P
   nsRect rect = GetRect();
   if (!rect.width || !rect.height)
   {
-    nsIFrame *nextFlow = nsnull;
     //if we have a 0 width or height then lets look for another frame that possibly has
     //the same content.  If we have no frames in flow then just let us return 'this' frame
-    if (NS_SUCCEEDED(GetNextInFlow(&nextFlow)) && nextFlow)
+    nsIFrame* nextFlow = GetNextInFlow();
+    if (nextFlow)
       return nextFlow->GetChildFrameContainingOffset(inContentOffset, inHint, outFrameContentOffset, outChildFrame);
   }
   *outChildFrame = this;
@@ -5262,12 +5258,11 @@ static void DisplayReflowEnterPrint(nsPresContext*          aPresContext,
     DR_state->PrettyUC(aReflowState.mComputedHeight, height);
     printf("c=%s,%s ", width, height);
 
-    nsIFrame* inFlow;
-    aFrame->GetPrevInFlow(&inFlow);
+    nsIFrame* inFlow = aFrame->GetPrevInFlow();
     if (inFlow) {
       printf("pif=%p ", (void*)inFlow);
     }
-    aFrame->GetNextInFlow(&inFlow);
+    inFlow = aFrame->GetNextInFlow();
     if (inFlow) {
       printf("nif=%p ", (void*)inFlow);
     }
diff --git a/mozilla/layout/generic/nsFrame.h b/mozilla/layout/generic/nsFrame.h
index 0a83d825ad7..1535e46fde4 100644
--- a/mozilla/layout/generic/nsFrame.h
+++ b/mozilla/layout/generic/nsFrame.h
@@ -232,9 +232,9 @@ public:
                                nsIAtom*        aAttribute,
                                PRInt32         aModType);
   NS_IMETHOD  IsSplittable(nsSplittableType& aIsSplittable) const;
-  NS_IMETHOD  GetPrevInFlow(nsIFrame** aPrevInFlow) const;
+  virtual nsIFrame* GetPrevInFlow() const;
   NS_IMETHOD  SetPrevInFlow(nsIFrame*);
-  NS_IMETHOD  GetNextInFlow(nsIFrame** aNextInFlow) const;
+  virtual nsIFrame* GetNextInFlow() const;
   NS_IMETHOD  SetNextInFlow(nsIFrame*);
   NS_IMETHOD  GetOffsetFromView(nsPresContext* aPresContext, nsPoint& aOffset, nsIView** aView) const;
   NS_IMETHOD  GetOriginToViewOffset(nsPresContext *aPresContext, nsPoint& aOffset, nsIView **aView) const;
diff --git a/mozilla/layout/generic/nsHTMLContainerFrame.cpp b/mozilla/layout/generic/nsHTMLContainerFrame.cpp
index cd1371dfc23..db2d194acee 100644
--- a/mozilla/layout/generic/nsHTMLContainerFrame.cpp
+++ b/mozilla/layout/generic/nsHTMLContainerFrame.cpp
@@ -248,7 +248,7 @@ HasTextFrameDescendant(nsPresContext* aPresContext, nsIFrame* aParent)
 static PRBool 
 HasTextFrameDescendantOrInFlow(nsPresContext* aPresContext, nsIFrame* aFrame)
 {
-  for (nsIFrame *f = aFrame->GetFirstInFlow(); f; f->GetNextInFlow(&f)) {
+  for (nsIFrame *f = aFrame->GetFirstInFlow(); f; f = f->GetNextInFlow()) {
     if (HasTextFrameDescendant(aPresContext, f))
       return PR_TRUE;
   }
@@ -311,8 +311,7 @@ nsHTMLContainerFrame::CreateNextInFlow(nsPresContext* aPresContext,
 {
   aNextInFlowResult = nsnull;
 
-  nsIFrame* nextInFlow;
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aFrame->GetNextInFlow();
   if (nsnull == nextInFlow) {
     // Create a continuation frame for the child frame and insert it
     // into our lines child list.
diff --git a/mozilla/layout/generic/nsHTMLReflowState.cpp b/mozilla/layout/generic/nsHTMLReflowState.cpp
index fe52fdb8ff4..065afb927af 100644
--- a/mozilla/layout/generic/nsHTMLReflowState.cpp
+++ b/mozilla/layout/generic/nsHTMLReflowState.cpp
@@ -1384,8 +1384,7 @@ CalcQuirkContainingBlockHeight(const nsHTMLReflowState& aReflowState)
       }
     }
     else if (nsLayoutAtoms::pageContentFrame == frameType) {
-      nsIFrame* prevInFlow;
-      rs->frame->GetPrevInFlow(&prevInFlow);
+      nsIFrame* prevInFlow = rs->frame->GetPrevInFlow();
       // only use the page content frame for a height basis if it is the first in flow
       if (prevInFlow) 
         break;
diff --git a/mozilla/layout/generic/nsIFrame.h b/mozilla/layout/generic/nsIFrame.h
index b8268bc076e..baee4f7ba37 100644
--- a/mozilla/layout/generic/nsIFrame.h
+++ b/mozilla/layout/generic/nsIFrame.h
@@ -825,9 +825,9 @@ public:
   /**
    * Flow member functions
    */
-  NS_IMETHOD  GetPrevInFlow(nsIFrame** aPrevInFlow) const = 0;
+  virtual nsIFrame* GetPrevInFlow() const = 0;
   NS_IMETHOD  SetPrevInFlow(nsIFrame*) = 0;
-  NS_IMETHOD  GetNextInFlow(nsIFrame** aNextInFlow) const = 0;
+  virtual nsIFrame* GetNextInFlow() const = 0;
   NS_IMETHOD  SetNextInFlow(nsIFrame*) = 0;
 
   /**
diff --git a/mozilla/layout/generic/nsImageFrame.cpp b/mozilla/layout/generic/nsImageFrame.cpp
index 110484e17e9..3c48bb1fc96 100644
--- a/mozilla/layout/generic/nsImageFrame.cpp
+++ b/mozilla/layout/generic/nsImageFrame.cpp
@@ -933,7 +933,7 @@ nsImageFrame::GetContinuationOffset(nscoord* aWidth) const
   }
 
   if (mPrevInFlow) {
-    for (nsIFrame* prevInFlow = mPrevInFlow ; prevInFlow; prevInFlow->GetPrevInFlow(&prevInFlow)) {
+    for (nsIFrame* prevInFlow = mPrevInFlow ; prevInFlow; prevInFlow = prevInFlow->GetPrevInFlow()) {
       nsRect rect = prevInFlow->GetRect();
       if (aWidth) {
         *aWidth = rect.width;
@@ -1019,12 +1019,7 @@ nsImageFrame::Reflow(nsPresContext*          aPresContext,
   aMetrics.descent = 0;
 
   if (aMetrics.mComputeMEW) {
-    // If we have a percentage based width, then our MEW is 0
-    if (eStyleUnit_Percent == aReflowState.mStylePosition->mWidth.GetUnit()) {
-      aMetrics.mMaxElementWidth = 0;
-    } else {
-      aMetrics.mMaxElementWidth = aMetrics.width;
-    }
+    aMetrics.SetMEWToActualWidth(aReflowState.mStylePosition->mWidth.GetUnit());
   }
   
   if (aMetrics.mFlags & NS_REFLOW_CALC_MAX_WIDTH) {
diff --git a/mozilla/layout/generic/nsInlineFrame.cpp b/mozilla/layout/generic/nsInlineFrame.cpp
index 1de294c267e..230abed746e 100644
--- a/mozilla/layout/generic/nsInlineFrame.cpp
+++ b/mozilla/layout/generic/nsInlineFrame.cpp
@@ -261,8 +261,7 @@ nsInlineFrame::RemoveFrame(nsPresContext* aPresContext,
       // When the parent is an inline frame we have a simple task - just
       // remove the frame from its parents list and generate a reflow
       // command.
-      nsIFrame* oldFrameNextInFlow;
-      aOldFrame->GetNextInFlow(&oldFrameNextInFlow);
+      nsIFrame* oldFrameNextInFlow = aOldFrame->GetNextInFlow();
       parent->mFrames.DestroyFrame(aPresContext, aOldFrame);
       aOldFrame = oldFrameNextInFlow;
       if (aOldFrame) {
@@ -514,8 +513,7 @@ nsInlineFrame::ReflowFrames(nsPresContext* aPresContext,
       // its parent frame pointer, too. Otherwise, if we reflow frame and it's
       // complete we'll fail when deleting its next-in-flow which is no longer
       // needed. This scenario doesn't happen often, but it can happen
-      nsIFrame* nextInFlow;
-      frame->GetNextInFlow(&nextInFlow);
+      nsIFrame* nextInFlow = frame->GetNextInFlow();
       while (nextInFlow) {
         // Since we only do lazy setting of parent pointers for the frame's
         // initial reflow, this frame can't have a next-in-flow. That means
@@ -523,7 +521,7 @@ nsInlineFrame::ReflowFrames(nsPresContext* aPresContext,
         // not, then something is wrong
         NS_ASSERTION(mFrames.ContainsFrame(nextInFlow), "unexpected flow");
         nextInFlow->SetParent(this);
-        nextInFlow->GetNextInFlow(&nextInFlow);
+        nextInFlow = nextInFlow->GetNextInFlow();
       }
     }
     rv = ReflowInlineFrame(aPresContext, aReflowState, irs, frame, aStatus);
diff --git a/mozilla/layout/generic/nsLineLayout.cpp b/mozilla/layout/generic/nsLineLayout.cpp
index 03e94b4c984..d0a8e470526 100644
--- a/mozilla/layout/generic/nsLineLayout.cpp
+++ b/mozilla/layout/generic/nsLineLayout.cpp
@@ -230,8 +230,7 @@ PRBool nsLineLayout::AllocateDeque()
 inline PRBool
 HasPrevInFlow(nsIFrame *aFrame)
 {
-  nsIFrame *prevInFlow;
-  aFrame->GetPrevInFlow(&prevInFlow);
+  nsIFrame *prevInFlow = aFrame->GetPrevInFlow();
   return prevInFlow != nsnull;
 }
 
@@ -1151,8 +1150,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
     // the frame is going to get reflowed again (and may end up wanting
     // a next-in-flow where it ends up).
     if (NS_FRAME_IS_COMPLETE(aReflowStatus)) {
-      nsIFrame* kidNextInFlow;
-      aFrame->GetNextInFlow(&kidNextInFlow);
+      nsIFrame* kidNextInFlow = aFrame->GetNextInFlow();
       if (nsnull != kidNextInFlow) {
         // Remove all of the childs next-in-flows. Make sure that we ask
         // the right parent to do the removal (it's possible that the
@@ -1203,8 +1201,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
       PRInt32 newEnd;
       aFrame->GetOffsets(start, newEnd);
       if (newEnd != end) {
-        nsIFrame* nextInFlow;
-        aFrame->GetNextInFlow(&nextInFlow);
+        nsIFrame* nextInFlow = aFrame->GetNextInFlow();
         if (nextInFlow) {
           nextInFlow->GetOffsets(start, end);
           nextInFlow->AdjustOffsetsForBidi(newEnd, end);
@@ -1387,11 +1384,9 @@ nsLineLayout::CanPlaceFrame(PerFrameData* pfd,
   // If this is a piece of text inside a letter frame...
   if (pfd->GetFlag(PFD_ISNONEMPTYTEXTFRAME)) {
     if (psd->mFrame && psd->mFrame->GetFlag(PFD_ISLETTERFRAME)) {
-      nsIFrame* prevInFlow;
-      psd->mFrame->mFrame->GetPrevInFlow(&prevInFlow);
+      nsIFrame* prevInFlow = psd->mFrame->mFrame->GetPrevInFlow();
       if (prevInFlow) {
-        nsIFrame* prevPrevInFlow;
-        prevInFlow->GetPrevInFlow(&prevPrevInFlow);
+        nsIFrame* prevPrevInFlow = prevInFlow->GetPrevInFlow();
         if (!prevPrevInFlow) {
           // And it's the first continuation of the letter frame...
           // Then make sure that the text fits
@@ -1402,11 +1397,9 @@ nsLineLayout::CanPlaceFrame(PerFrameData* pfd,
   }
   else if (pfd->GetFlag(PFD_ISLETTERFRAME)) {
     // If this is the first continuation of the letter frame...
-    nsIFrame* prevInFlow;
-    pfd->mFrame->GetPrevInFlow(&prevInFlow);
+    nsIFrame* prevInFlow = pfd->mFrame->GetPrevInFlow();
     if (prevInFlow) {
-      nsIFrame* prevPrevInFlow;
-      prevInFlow->GetPrevInFlow(&prevPrevInFlow);
+      nsIFrame* prevPrevInFlow = prevInFlow->GetPrevInFlow();
       if (!prevPrevInFlow) {
         return PR_TRUE;
       }
@@ -1929,10 +1922,8 @@ nsLineLayout::VerticalAlignFrames(PerSpanData* psd)
   // - it has a prev-in-flow
   // - it has no next in flow
   // - it's zero sized
-  nsIFrame* spanNextInFlow;
-  spanFrame->GetNextInFlow(&spanNextInFlow);
-  nsIFrame* spanPrevInFlow;
-  spanFrame->GetPrevInFlow(&spanPrevInFlow);
+  nsIFrame* spanNextInFlow = spanFrame->GetNextInFlow();
+  nsIFrame* spanPrevInFlow = spanFrame->GetPrevInFlow();
   PRBool emptyContinuation = spanPrevInFlow && !spanNextInFlow &&
     (0 == spanFramePFD->mBounds.width) && (0 == spanFramePFD->mBounds.height);
 
diff --git a/mozilla/layout/generic/nsPageContentFrame.cpp b/mozilla/layout/generic/nsPageContentFrame.cpp
index 1e76bba764a..b33c5fef664 100644
--- a/mozilla/layout/generic/nsPageContentFrame.cpp
+++ b/mozilla/layout/generic/nsPageContentFrame.cpp
@@ -117,15 +117,8 @@ NS_IMETHODIMP nsPageContentFrame::Reflow(nsPresContext*   aPresContext,
       // Place and size the child
       FinishReflowChild(frame, aPresContext, &kidReflowState, aDesiredSize, 0, 0, 0);
 
-#ifdef NS_DEBUG
-      // Is the frame complete?
-      if (NS_FRAME_IS_COMPLETE(aStatus)) {
-        nsIFrame* childNextInFlow;
-
-        frame->GetNextInFlow(&childNextInFlow);
-        NS_ASSERTION(nsnull == childNextInFlow, "bad child flow list");
-      }
-#endif
+      NS_ASSERTION(!NS_FRAME_IS_COMPLETE(aStatus) ||
+                   !frame->GetNextInFlow(), "bad child flow list");
 
 #ifdef DEBUG_PRINTING
       nsRect r = frame->GetRect();
diff --git a/mozilla/layout/generic/nsPageFrame.cpp b/mozilla/layout/generic/nsPageFrame.cpp
index 14941e08a23..97181eb3dd4 100644
--- a/mozilla/layout/generic/nsPageFrame.cpp
+++ b/mozilla/layout/generic/nsPageFrame.cpp
@@ -221,15 +221,8 @@ NS_IMETHODIMP nsPageFrame::Reflow(nsPresContext*          aPresContext,
         view->GetViewManager()->SetViewChildClipRegion(view, &region);
       }
 
-#ifdef NS_DEBUG
-      // Is the frame complete?
-      if (NS_FRAME_IS_COMPLETE(aStatus)) {
-        nsIFrame* childNextInFlow;
-
-        frame->GetNextInFlow(&childNextInFlow);
-        NS_ASSERTION(nsnull == childNextInFlow, "bad child flow list");
-      }
-#endif
+      NS_ASSERTION(!NS_FRAME_IS_COMPLETE(aStatus) ||
+                   !frame->GetNextInFlow(), "bad child flow list");
     }
     PR_PL(("PageFrame::Reflow %p ", this));
     PR_PL(("[%d,%d][%d,%d]\n", aDesiredSize.width, aDesiredSize.height, aReflowState.availableWidth, aReflowState.availableHeight));
diff --git a/mozilla/layout/generic/nsSelection.cpp b/mozilla/layout/generic/nsSelection.cpp
index 0bbef348a1d..6d3560a4732 100644
--- a/mozilla/layout/generic/nsSelection.cpp
+++ b/mozilla/layout/generic/nsSelection.cpp
@@ -4839,7 +4839,8 @@ nsTypedSelection::selectFrames(nsPresContext* aPresContext,
         while (!frameRect.width || !frameRect.height)
         {
           //try to notify next in flow that its content is selected.
-          if (NS_SUCCEEDED(frame->GetNextInFlow(&frame)) && frame)
+          frame = frame->GetNextInFlow();
+          if (frame)
           {
             frameRect = frame->GetRect();
             frame->SetSelected(aPresContext, nsnull,aFlags,eSpreadDown);
diff --git a/mozilla/layout/generic/nsSimplePageSequence.cpp b/mozilla/layout/generic/nsSimplePageSequence.cpp
index 1dcab054be3..10af040c3a7 100644
--- a/mozilla/layout/generic/nsSimplePageSequence.cpp
+++ b/mozilla/layout/generic/nsSimplePageSequence.cpp
@@ -428,8 +428,7 @@ nsSimplePageSequenceFrame::Reflow(nsPresContext*          aPresContext,
       y += deadSpaceGap;
 
       // Is the page complete?
-      nsIFrame* kidNextInFlow;
-      kidFrame->GetNextInFlow(&kidNextInFlow);
+      nsIFrame* kidNextInFlow = kidFrame->GetNextInFlow();
 
       if (NS_FRAME_IS_COMPLETE(status)) {
         NS_ASSERTION(nsnull == kidNextInFlow, "bad child flow list");
diff --git a/mozilla/layout/generic/nsSplittableFrame.cpp b/mozilla/layout/generic/nsSplittableFrame.cpp
index 10cf15ee0e1..c13d5fef751 100644
--- a/mozilla/layout/generic/nsSplittableFrame.cpp
+++ b/mozilla/layout/generic/nsSplittableFrame.cpp
@@ -78,10 +78,9 @@ nsSplittableFrame::IsSplittable(nsSplittableType& aIsSplittable) const
   return NS_OK;
 }
 
-NS_METHOD nsSplittableFrame::GetPrevInFlow(nsIFrame** aPrevInFlow) const
+nsIFrame* nsSplittableFrame::GetPrevInFlow() const
 {
-  *aPrevInFlow = mPrevInFlow;
-  return NS_OK;
+  return mPrevInFlow;
 }
 
 NS_METHOD nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
@@ -90,10 +89,9 @@ NS_METHOD nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
   return NS_OK;
 }
 
-NS_METHOD nsSplittableFrame::GetNextInFlow(nsIFrame** aNextInFlow) const
+nsIFrame* nsSplittableFrame::GetNextInFlow() const
 {
-  *aNextInFlow = mNextInFlow;
-  return NS_OK;
+  return mNextInFlow;
 }
 
 NS_METHOD nsSplittableFrame::SetNextInFlow(nsIFrame* aFrame)
@@ -126,11 +124,8 @@ nsIFrame* nsSplittableFrame::GetLastInFlow() const
 void
 nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
 {
-  nsIFrame* prevInFlow;
-  nsIFrame* nextInFlow;
-
-  aFrame->GetPrevInFlow(&prevInFlow);
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
+  nsIFrame* nextInFlow = aFrame->GetNextInFlow();
 
   if (prevInFlow) {
     prevInFlow->SetNextInFlow(nextInFlow);
@@ -148,25 +143,13 @@ nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
 void
 nsSplittableFrame::BreakFromPrevFlow(nsIFrame* aFrame)
 {
-  nsIFrame* prevInFlow;
-
-  aFrame->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
   if (prevInFlow) {
     prevInFlow->SetNextInFlow(nsnull);
     aFrame->SetPrevInFlow(nsnull);
   }
 }
 
-nsIFrame * nsSplittableFrame::GetPrevInFlow() 
-{
-  return mPrevInFlow;
-}
-
-nsIFrame * nsSplittableFrame::GetNextInFlow()
-{
-   return mNextInFlow;
-} 
-
 #ifdef DEBUG
 void
 nsSplittableFrame::DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, PRInt32 aIndent, PRBool aIncludeStyleData)
diff --git a/mozilla/layout/generic/nsSplittableFrame.h b/mozilla/layout/generic/nsSplittableFrame.h
index 801ba0f64ee..769344d1887 100644
--- a/mozilla/layout/generic/nsSplittableFrame.h
+++ b/mozilla/layout/generic/nsSplittableFrame.h
@@ -54,9 +54,9 @@ public:
   NS_IMETHOD Destroy(nsPresContext* aPresContext);
 
   // Flow member functions.
-  NS_IMETHOD  GetPrevInFlow(nsIFrame** aPrevInFlow) const;
+  virtual nsIFrame* GetPrevInFlow() const;
   NS_IMETHOD  SetPrevInFlow(nsIFrame*);
-  NS_IMETHOD  GetNextInFlow(nsIFrame** aNextInFlow) const;
+  virtual nsIFrame*  GetNextInFlow() const;
   NS_IMETHOD  SetNextInFlow(nsIFrame*);
 
   /**
@@ -76,9 +76,6 @@ public:
   // Detach from previous frame in flow
   static void BreakFromPrevFlow(nsIFrame* aFrame);
 
-  nsIFrame*   GetPrevInFlow();
-  nsIFrame*   GetNextInFlow();
-
 protected:
 #ifdef DEBUG
   virtual void DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, PRInt32 aIndent, PRBool aIncludeStyleData);
diff --git a/mozilla/layout/generic/nsTextFrame.cpp b/mozilla/layout/generic/nsTextFrame.cpp
index e44c76e6829..8bad9682b82 100644
--- a/mozilla/layout/generic/nsTextFrame.cpp
+++ b/mozilla/layout/generic/nsTextFrame.cpp
@@ -404,9 +404,8 @@ public:
                                   nsIContent*     aChild,
                                   PRBool          aAppend);
 
-  NS_IMETHOD GetNextInFlow(nsIFrame** aNextInFlow) const {
-    *aNextInFlow = mNextInFlow;
-    return NS_OK;
+  virtual nsIFrame* GetNextInFlow() const {
+    return mNextInFlow;
   }
   NS_IMETHOD SetNextInFlow(nsIFrame* aNextInFlow) {
     mNextInFlow = aNextInFlow;
@@ -843,9 +842,8 @@ public:
 
   NS_IMETHOD Destroy(nsPresContext* aPresContext);
 
-  NS_IMETHOD GetPrevInFlow(nsIFrame** aPrevInFlow) const {
-    *aPrevInFlow = mPrevInFlow;
-    return NS_OK;
+  virtual nsIFrame* GetPrevInFlow() const {
+    return mPrevInFlow;
   }
   NS_IMETHOD SetPrevInFlow(nsIFrame* aPrevInFlow) {
     mPrevInFlow = aPrevInFlow;
@@ -925,7 +923,7 @@ nsContinuingTextFrame::GetFirstInFlow() const
                                      NS_STATIC_CAST(const nsIFrame*, this));
   do {
     firstInFlow = previous;
-    firstInFlow->GetPrevInFlow(&previous);
+    previous = firstInFlow->GetPrevInFlow();
   } while (previous);
   return firstInFlow;
 }
@@ -3568,7 +3566,6 @@ nsTextFrame::SetSelected(nsPresContext* aPresContext,
                          PRBool aSelected,
                          nsSpread aSpread)
 {
-  nsresult result;
   if (aSelected && ParentDisablesSelection())
     return NS_OK;
 
@@ -3685,20 +3682,15 @@ nsTextFrame::SetSelected(nsPresContext* aPresContext,
   }
   if (aSpread == eSpreadDown)
   {
-    nsIFrame *frame;
-    GetPrevInFlow(&frame);
+    nsIFrame* frame = GetPrevInFlow();
     while(frame){
       frame->SetSelected(aPresContext, aRange,aSelected,eSpreadNone);
-      result = frame->GetPrevInFlow(&frame);
-      if (NS_FAILED(result))
-        break;
+      frame = frame->GetPrevInFlow();
     }
-    GetNextInFlow(&frame);
+    frame = GetNextInFlow();
     while (frame){
       frame->SetSelected(aPresContext, aRange,aSelected,eSpreadNone);
-      result = frame->GetNextInFlow(&frame);
-      if (NS_FAILED(result))
-        break;
+      frame = frame->GetNextInFlow();
     }
 #ifdef IBMBIDI
     if ((mState & NS_FRAME_IS_BIDI) &&
@@ -3831,7 +3823,6 @@ nsTextFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset,
 {
   if (nsnull == outChildFrame)
     return NS_ERROR_NULL_POINTER;
-  nsresult result;
   PRInt32 contentOffset = inContentOffset;
   
   if (contentOffset != -1) //-1 signified the end of the current content
@@ -3840,8 +3831,7 @@ nsTextFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset,
   if ((contentOffset > mContentLength) || ((contentOffset == mContentLength) && inHint) )
   {
     //this is not the frame we are looking for.
-    nsIFrame *nextInFlow;
-    GetNextInFlow(&nextInFlow);
+    nsIFrame* nextInFlow = GetNextInFlow();
     if (nextInFlow)
     {
       return nextInFlow->GetChildFrameContainingOffset(inContentOffset, inHint, outFrameContentOffset, outChildFrame);
@@ -3873,12 +3863,12 @@ nsTextFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset,
 
   if (inContentOffset < mContentOffset) //could happen with floats!
   {
-    result = GetPrevInFlow(outChildFrame);
-    if (NS_SUCCEEDED(result) && *outChildFrame)
+    *outChildFrame = GetPrevInFlow();
+    if (*outChildFrame)
       return (*outChildFrame)->GetChildFrameContainingOffset(inContentOffset, inHint,
         outFrameContentOffset,outChildFrame);
     else
-      return result;
+      return NS_OK; //this can't be the right thing to do?
   }
   
   *outFrameContentOffset = contentOffset;
@@ -3915,7 +3905,7 @@ nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos)
     }
     else
 #endif
-    GetNextInFlow(&nextInFlow);
+    nextInFlow = GetNextInFlow();
     if (!nextInFlow){
       NS_ASSERTION(PR_FALSE,"nsTextFrame::PeekOffset no more flow \n");
       return NS_ERROR_INVALID_ARG;
@@ -4040,7 +4030,7 @@ nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos)
 
           if (i <0){
             found = PR_FALSE;
-            GetPrevInFlow(&frameUsed);
+            frameUsed = GetPrevInFlow();
             start = mContentOffset;
             aPos->mContentOffset = start;//in case next call fails we stop at this offset
           }
@@ -4095,7 +4085,7 @@ nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos)
   */
           if (i > mContentLength){
             found = PR_FALSE;
-            GetNextInFlow(&frameUsed);
+            frameUsed = GetNextInFlow();
             start = mContentOffset + mContentLength;
             aPos->mContentOffset = start;//in case next call fails we stop at this offset
           }
@@ -4250,7 +4240,7 @@ nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos)
           } 
 
   TryNextFrame:        
-          GetNextInFlow(&frameUsed);
+          frameUsed = GetNextInFlow();
           start = 0;
         }
       }
@@ -4398,7 +4388,7 @@ nsTextFrame::CheckVisibility(nsPresContext* aContext, PRInt32 aStartIndex, PRInt
     rv = NS_OK;
     while (!aFinished && nextInFlow && NS_SUCCEEDED(rv) && !*_retval) //while we havent found anything visible
     {
-      rv = nextInFlow->GetNextInFlow(&nextInFlow);
+      nextInFlow = nextInFlow->GetNextInFlow();
       if (nextInFlow)
       {
         rv = nextInFlow->CheckVisibility(aContext,aStartIndex,aEndIndex,PR_FALSE,aFinished,_retval);
@@ -5186,9 +5176,7 @@ nsTextFrame::Reflow(nsPresContext*          aPresContext,
 
   // Get starting offset into the content
   PRInt32 startingOffset = 0;
-  nsIFrame* prevInFlow;
-
-  GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = GetPrevInFlow();
   if (nsnull != prevInFlow) {
     nsTextFrame* prev = (nsTextFrame*)prevInFlow;
     startingOffset = prev->mContentOffset + prev->mContentLength;
@@ -5912,8 +5900,7 @@ nsTextFrame::List(nsPresContext* aPresContext, FILE* out, PRInt32 aIndent) const
   if (nsnull != mNextSibling) {
     fprintf(out, " next=%p", NS_STATIC_CAST(void*, mNextSibling));
   }
-  nsIFrame* prevInFlow;
-  GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = GetPrevInFlow();
   if (nsnull != prevInFlow) {
     fprintf(out, " prev-in-flow=%p", NS_STATIC_CAST(void*, prevInFlow));
   }
diff --git a/mozilla/layout/html/base/src/nsBlockFrame.cpp b/mozilla/layout/html/base/src/nsBlockFrame.cpp
index eb78a3b9704..91c7e167f49 100644
--- a/mozilla/layout/html/base/src/nsBlockFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBlockFrame.cpp
@@ -827,8 +827,7 @@ nsBlockFrame::Reflow(nsPresContext*          aPresContext,
   NS_ASSERTION(NS_SUCCEEDED(rv), "reflow dirty lines failed");
   if (NS_FAILED(rv)) return rv;
 
-  nsIFrame* nextInFlow;
-  GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = GetNextInFlow();
   if (nextInFlow && NS_FRAME_IS_NOT_COMPLETE(state.mReflowStatus)) {
     if (GetOverflowLines() || GetOverflowPlaceholders()) {
       state.mReflowStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
@@ -1243,7 +1242,7 @@ nsBlockFrame::ComputeFinalSize(const nsHTMLReflowState& aReflowState,
       if (mPrevInFlow) {
         // Reduce the height by the height of prev-in-flows. The last-in-flow will automatically
         // pick up the bottom border/padding, since it was part of the original aMetrics.height.
-        for (nsIFrame* prev = mPrevInFlow; prev; prev->GetPrevInFlow(&prev)) {
+        for (nsIFrame* prev = mPrevInFlow; prev; prev = prev->GetPrevInFlow()) {
           aMetrics.height -= prev->GetRect().height;
           // XXX: All block level next-in-flows have borderPadding.top applied to them (bug 174688). 
           // The following should be removed when this gets fixed. bug 174688 prevents us from honoring 
@@ -1461,8 +1460,7 @@ nsBlockFrame::PrepareChildIncrementalReflow(nsBlockReflowState& aState)
         // of the continuations. This will allow the incremental
         // reflow to arrive at the target frame during the first-pass
         // unconstrained reflow.
-        nsIFrame *prevInFlow;
-        (*iter)->GetPrevInFlow(&prevInFlow);
+        nsIFrame *prevInFlow = (*iter)->GetPrevInFlow();
         if (prevInFlow)
           RetargetInlineIncrementalReflow(iter, line, prevInFlow);
       }
@@ -1507,7 +1505,7 @@ nsBlockFrame::RetargetInlineIncrementalReflow(nsReflowPath::iterator &aTarget,
       break;
 
     *aTarget = aPrevInFlow;
-    aPrevInFlow->GetPrevInFlow(&aPrevInFlow);
+    aPrevInFlow = aPrevInFlow->GetPrevInFlow();
 
 #ifdef DEBUG
     // Paranoia. Ensure that the prev-in-flow is really in the
@@ -1548,7 +1546,7 @@ nsBlockFrame::RetargetInlineIncrementalReflow(nsReflowPath::iterator &aTarget,
       PRInt32 count = lineCount;
       nsIFrame *prevInFlow;
       do {
-        frame->GetPrevInFlow(&prevInFlow);
+        prevInFlow = frame->GetPrevInFlow();
       } while (--count >= 0 && prevInFlow && (frame = prevInFlow));
 
       path->ReplaceElementAt(frame, i);
@@ -2975,8 +2973,7 @@ nsBlockFrame::ReflowBlockFrame(nsBlockReflowState& aState,
   // apply its top margin because its not significant. Otherwise, dig
   // deeper.
   PRBool applyTopMargin = PR_FALSE;
-  nsIFrame* framePrevInFlow;
-  frame->GetPrevInFlow(&framePrevInFlow);
+  nsIFrame* framePrevInFlow = frame->GetPrevInFlow();
   if (nsnull == framePrevInFlow) {
     applyTopMargin = ShouldApplyTopMargin(aState, aLine);
   }
@@ -4746,8 +4743,7 @@ nsBlockFrame::DoRemoveOutOfFlowFrame(nsPresContext* aPresContext,
                                      nsIFrame*       aFrame)
 {
   // First remove aFrame's next in flow
-  nsIFrame* nextInFlow;
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aFrame->GetNextInFlow();
   if (nextInFlow) {
     nsBlockFrame::DoRemoveOutOfFlowFrame(aPresContext, nextInFlow);
   }
@@ -4890,8 +4886,7 @@ nsBlockFrame::DoRemoveFrame(nsPresContext* aPresContext,
 
       // Destroy frame; capture its next-in-flow first in case we need
       // to destroy that too.
-      nsIFrame* nextInFlow;
-      aDeletedFrame->GetNextInFlow(&nextInFlow);
+      nsIFrame* nextInFlow = aDeletedFrame->GetNextInFlow();
 #ifdef NOISY_REMOVE_FRAME
       printf("DoRemoveFrame: line=%p frame=", line);
       nsFrame::ListTag(stdout, aDeletedFrame);
@@ -4973,8 +4968,7 @@ void
 nsBlockFrame::DeleteNextInFlowChild(nsPresContext* aPresContext,
                                     nsIFrame*       aNextInFlow)
 {
-  nsIFrame* prevInFlow;
-  aNextInFlow->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aNextInFlow->GetPrevInFlow();
   NS_PRECONDITION(prevInFlow, "bad next-in-flow");
   NS_PRECONDITION(IsChild(aNextInFlow), "bad geometric parent");
 
@@ -4997,8 +4991,7 @@ nsBlockFrame::ReflowFloat(nsBlockReflowState& aState,
                           nsReflowStatus&     aReflowStatus)
 {
   // Delete the placeholder's next in flows, if any
-  nsIFrame* nextInFlow;
-  aPlaceholder->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aPlaceholder->GetNextInFlow();
   if (nextInFlow) {
     // If aPlaceholder's parent is an inline, nextInFlow's will be a block.
     NS_STATIC_CAST(nsHTMLContainerFrame*, nextInFlow->GetParent())
@@ -5025,8 +5018,7 @@ nsBlockFrame::ReflowFloat(nsBlockReflowState& aState,
   else {
     const nsStyleDisplay* floatDisplay = floatFrame->GetStyleDisplay();
 
-    nsIFrame* prevInFlow;
-    floatFrame->GetPrevInFlow(&prevInFlow);
+    nsIFrame* prevInFlow = floatFrame->GetPrevInFlow();
     // if the float is continued, constrain its width to the prev-in-flow's width
     if (prevInFlow) {
       availWidth = prevInFlow->GetRect().width;
@@ -5168,8 +5160,7 @@ nsBlockFrame::ReflowFloat(nsBlockReflowState& aState,
   // If the placeholder was continued and its first-in-flow was followed by a 
   // <BR>, then cache the <BR>'s break type in aState.mFloatBreakType so that
   // the next frame after the placeholder can combine that break type with its own
-  nsIFrame* prevPlaceholder = nsnull;
-  aPlaceholder->GetPrevInFlow(&prevPlaceholder);
+  nsIFrame* prevPlaceholder = aPlaceholder->GetPrevInFlow();
   if (prevPlaceholder) {
     // the break occurs only after the last continued placeholder
     PRBool lastPlaceholder = PR_TRUE;
@@ -6155,8 +6146,7 @@ nsBlockFrame::IsChild(nsIFrame* aFrame)
   // and placeholders don't satisfy InSiblingList().  
   PRBool skipLineList    = PR_FALSE;
   PRBool skipSiblingList = PR_FALSE;
-  nsIFrame* prevInFlow;
-  aFrame->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
   if (prevInFlow) {
     nsFrameState state = aFrame->GetStateBits();
     skipLineList    = (state & NS_FRAME_OUT_OF_FLOW); 
@@ -6359,7 +6349,7 @@ nsBlockFrame::RenumberListsInBlock(nsPresContext* aPresContext,
     }
 
     // Advance to the next continuation
-    aBlockFrame->GetNextInFlow((nsIFrame**) &aBlockFrame);
+    aBlockFrame = NS_STATIC_CAST(nsBlockFrame*, aBlockFrame->GetNextInFlow());
   }
 
   return renumberedABullet;
diff --git a/mozilla/layout/html/base/src/nsBlockReflowContext.cpp b/mozilla/layout/html/base/src/nsBlockReflowContext.cpp
index 1117e1c2fae..021b9a25b6a 100644
--- a/mozilla/layout/html/base/src/nsBlockReflowContext.cpp
+++ b/mozilla/layout/html/base/src/nsBlockReflowContext.cpp
@@ -617,8 +617,7 @@ nsBlockReflowContext::ReflowBlock(const nsRect&       aSpace,
     // the frame is going to get reflowed again (and may end up wanting
     // a next-in-flow where it ends up), unless it is an out of flow frame.
     if (NS_FRAME_IS_COMPLETE(aFrameReflowStatus)) {
-      nsIFrame* kidNextInFlow;
-      mFrame->GetNextInFlow(&kidNextInFlow);
+      nsIFrame* kidNextInFlow = mFrame->GetNextInFlow();
       if (nsnull != kidNextInFlow) {
         // Remove all of the childs next-in-flows. Make sure that we ask
         // the right parent to do the removal (it's possible that the
diff --git a/mozilla/layout/html/base/src/nsBlockReflowState.cpp b/mozilla/layout/html/base/src/nsBlockReflowState.cpp
index c644b5d9a86..0a3accdb217 100644
--- a/mozilla/layout/html/base/src/nsBlockReflowState.cpp
+++ b/mozilla/layout/html/base/src/nsBlockReflowState.cpp
@@ -99,7 +99,7 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
   mReflowStatus = NS_FRAME_COMPLETE;
 
   mPresContext = aPresContext;
-  mBlock->GetNextInFlow(NS_REINTERPRET_CAST(nsIFrame**, &mNextInFlow));
+  mNextInFlow = NS_STATIC_CAST(nsBlockFrame*, mBlock->GetNextInFlow());
   mKidXMost = 0;
 
   // Compute content area width (the content area is inside the border
@@ -953,17 +953,15 @@ nsBlockReflowState::FlowAndPlaceFloat(nsFloatCache*   aFloatCache,
   }
   // If the float is continued, it will get the same absolute x value as its prev-in-flow
   nsRect prevRect(0,0,0,0);
-  nsIFrame* prevInFlow;
-  floatFrame->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = floatFrame->GetPrevInFlow();
   if (prevInFlow) {
     prevRect = prevInFlow->GetRect();
 
-    nsIFrame *placeParentPrev, *prevPlace;
     // If prevInFlow's placeholder is in a block that wasn't continued, we need to adjust 
     // prevRect.x to account for the missing frame offsets.
     nsIFrame* placeParent = placeholder->GetParent();
-    placeParent->GetPrevInFlow(&placeParentPrev);
-    prevPlace =
+    nsIFrame* placeParentPrev = placeParent->GetPrevInFlow();
+    nsIFrame* prevPlace =
       mPresContext->FrameManager()->GetPlaceholderFrameFor(prevInFlow);
 
     nsIFrame* prevPlaceParent = prevPlace->GetParent();
diff --git a/mozilla/layout/html/base/src/nsContainerFrame.cpp b/mozilla/layout/html/base/src/nsContainerFrame.cpp
index 0ce9fd3b615..e065b06d262 100644
--- a/mozilla/layout/html/base/src/nsContainerFrame.cpp
+++ b/mozilla/layout/html/base/src/nsContainerFrame.cpp
@@ -991,8 +991,7 @@ nsContainerFrame::ReflowChild(nsIFrame*                aKidFrame,
   // If the reflow was successful and the child frame is complete, delete any
   // next-in-flows
   if (NS_SUCCEEDED(result) && NS_FRAME_IS_COMPLETE(aStatus)) {
-    nsIFrame* kidNextInFlow;
-    aKidFrame->GetNextInFlow(&kidNextInFlow);
+    nsIFrame* kidNextInFlow = aKidFrame->GetNextInFlow();
     if (nsnull != kidNextInFlow) {
       // Remove all of the childs next-in-flows. Make sure that we ask
       // the right parent to do the removal (it's possible that the
@@ -1107,15 +1106,13 @@ void
 nsContainerFrame::DeleteNextInFlowChild(nsPresContext* aPresContext,
                                         nsIFrame*       aNextInFlow)
 {
-  nsIFrame* prevInFlow;
-  aNextInFlow->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aNextInFlow->GetPrevInFlow();
   NS_PRECONDITION(prevInFlow, "bad prev-in-flow");
   NS_PRECONDITION(mFrames.ContainsFrame(aNextInFlow), "bad geometric parent");
 
   // If the next-in-flow has a next-in-flow then delete it, too (and
   // delete it first).
-  nsIFrame* nextNextInFlow;
-  aNextInFlow->GetNextInFlow(&nextNextInFlow);
+  nsIFrame* nextNextInFlow = aNextInFlow->GetNextInFlow();
   if (nextNextInFlow) {
     NS_STATIC_CAST(nsContainerFrame*, nextNextInFlow->GetParent())
       ->DeleteNextInFlowChild(aPresContext, nextNextInFlow);
@@ -1153,11 +1150,7 @@ nsContainerFrame::DeleteNextInFlowChild(nsPresContext* aPresContext,
   // Delete the next-in-flow frame and its descendants.
   aNextInFlow->Destroy(aPresContext);
 
-#ifdef NS_DEBUG
-  nsIFrame* nextInFlow;
-  prevInFlow->GetNextInFlow(&nextInFlow);
-  NS_POSTCONDITION(!nextInFlow, "non null next-in-flow");
-#endif
+  NS_POSTCONDITION(!prevInFlow->GetNextInFlow(), "non null next-in-flow");
 }
 
 nsIFrame*
diff --git a/mozilla/layout/html/base/src/nsFirstLetterFrame.cpp b/mozilla/layout/html/base/src/nsFirstLetterFrame.cpp
index 3cbf8c847ac..11a672dce8e 100644
--- a/mozilla/layout/html/base/src/nsFirstLetterFrame.cpp
+++ b/mozilla/layout/html/base/src/nsFirstLetterFrame.cpp
@@ -292,8 +292,7 @@ nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
   // Create a continuation or remove existing continuations based on
   // the reflow completion status.
   if (NS_FRAME_IS_COMPLETE(aReflowStatus)) {
-    nsIFrame* kidNextInFlow;
-    kid->GetNextInFlow(&kidNextInFlow);
+    nsIFrame* kidNextInFlow = kid->GetNextInFlow();
     if (kidNextInFlow) {
       // Remove all of the childs next-in-flows
       NS_STATIC_CAST(nsContainerFrame*, kidNextInFlow->GetParent())
diff --git a/mozilla/layout/html/base/src/nsFrame.cpp b/mozilla/layout/html/base/src/nsFrame.cpp
index a50cbdd7021..2d0501504bb 100644
--- a/mozilla/layout/html/base/src/nsFrame.cpp
+++ b/mozilla/layout/html/base/src/nsFrame.cpp
@@ -1221,9 +1221,8 @@ ContentContainsPoint(nsPresContext *aPresContext,
       return PR_TRUE;
     }
 
-    rv = frame->GetNextInFlow(&frame);
+    frame = frame->GetNextInFlow();
 
-    if (NS_FAILED(rv)) return PR_FALSE;
   }
 
   return PR_FALSE;
@@ -2100,8 +2099,7 @@ nsFrame::DidReflow(nsPresContext*           aPresContext,
       aReflowState->mStylePosition                                     && // percent height
       (eStyleUnit_Percent == aReflowState->mStylePosition->mHeight.GetUnit())) {
 
-    nsIFrame* prevInFlow;
-    GetPrevInFlow(&prevInFlow);
+    nsIFrame* prevInFlow = GetPrevInFlow();
     if (!prevInFlow) { // 1st in flow
       aReflowState->mPercentHeightObserver->NotifyPercentHeight(*aReflowState);
     }
@@ -2181,10 +2179,9 @@ NS_IMETHODIMP nsFrame::IsSplittable(nsSplittableType& aIsSplittable) const
   return NS_OK;
 }
 
-NS_IMETHODIMP nsFrame::GetPrevInFlow(nsIFrame** aPrevInFlow) const
+nsIFrame* nsFrame::GetPrevInFlow() const
 {
-  *aPrevInFlow = nsnull;
-  return NS_OK;
+  return nsnull;
 }
 
 NS_IMETHODIMP nsFrame::SetPrevInFlow(nsIFrame* aPrevInFlow)
@@ -2198,10 +2195,9 @@ NS_IMETHODIMP nsFrame::SetPrevInFlow(nsIFrame* aPrevInFlow)
   return NS_OK;
 }
 
-NS_IMETHODIMP nsFrame::GetNextInFlow(nsIFrame** aNextInFlow) const
+nsIFrame* nsFrame::GetNextInFlow() const
 {
-  *aNextInFlow = nsnull;
-  return NS_OK;
+  return nsnull;
 }
 
 NS_IMETHODIMP nsFrame::SetNextInFlow(nsIFrame*)
@@ -3042,10 +3038,10 @@ nsFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset, PRBool inHint, P
   nsRect rect = GetRect();
   if (!rect.width || !rect.height)
   {
-    nsIFrame *nextFlow = nsnull;
     //if we have a 0 width or height then lets look for another frame that possibly has
     //the same content.  If we have no frames in flow then just let us return 'this' frame
-    if (NS_SUCCEEDED(GetNextInFlow(&nextFlow)) && nextFlow)
+    nsIFrame* nextFlow = GetNextInFlow();
+    if (nextFlow)
       return nextFlow->GetChildFrameContainingOffset(inContentOffset, inHint, outFrameContentOffset, outChildFrame);
   }
   *outChildFrame = this;
@@ -5262,12 +5258,11 @@ static void DisplayReflowEnterPrint(nsPresContext*          aPresContext,
     DR_state->PrettyUC(aReflowState.mComputedHeight, height);
     printf("c=%s,%s ", width, height);
 
-    nsIFrame* inFlow;
-    aFrame->GetPrevInFlow(&inFlow);
+    nsIFrame* inFlow = aFrame->GetPrevInFlow();
     if (inFlow) {
       printf("pif=%p ", (void*)inFlow);
     }
-    aFrame->GetNextInFlow(&inFlow);
+    inFlow = aFrame->GetNextInFlow();
     if (inFlow) {
       printf("nif=%p ", (void*)inFlow);
     }
diff --git a/mozilla/layout/html/base/src/nsFrame.h b/mozilla/layout/html/base/src/nsFrame.h
index 0a83d825ad7..1535e46fde4 100644
--- a/mozilla/layout/html/base/src/nsFrame.h
+++ b/mozilla/layout/html/base/src/nsFrame.h
@@ -232,9 +232,9 @@ public:
                                nsIAtom*        aAttribute,
                                PRInt32         aModType);
   NS_IMETHOD  IsSplittable(nsSplittableType& aIsSplittable) const;
-  NS_IMETHOD  GetPrevInFlow(nsIFrame** aPrevInFlow) const;
+  virtual nsIFrame* GetPrevInFlow() const;
   NS_IMETHOD  SetPrevInFlow(nsIFrame*);
-  NS_IMETHOD  GetNextInFlow(nsIFrame** aNextInFlow) const;
+  virtual nsIFrame* GetNextInFlow() const;
   NS_IMETHOD  SetNextInFlow(nsIFrame*);
   NS_IMETHOD  GetOffsetFromView(nsPresContext* aPresContext, nsPoint& aOffset, nsIView** aView) const;
   NS_IMETHOD  GetOriginToViewOffset(nsPresContext *aPresContext, nsPoint& aOffset, nsIView **aView) const;
diff --git a/mozilla/layout/html/base/src/nsFrameManager.cpp b/mozilla/layout/html/base/src/nsFrameManager.cpp
index 205e4111135..99933fe8e36 100644
--- a/mozilla/layout/html/base/src/nsFrameManager.cpp
+++ b/mozilla/layout/html/base/src/nsFrameManager.cpp
@@ -1498,8 +1498,7 @@ nsFrameManager::ReResolveStyleContext(nsPresContext    *aPresContext,
           localContent->IsContentOfType(nsIContent::eELEMENT)) {
         // Check for a new :before pseudo and an existing :before
         // frame, but only if the frame is the first-in-flow.
-        nsIFrame* prevInFlow = nsnull;
-        aFrame->GetPrevInFlow(&prevInFlow);
+        nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
         if (!prevInFlow) {
           // Checking for a :before frame is cheaper than getting the
           // :before style context.
@@ -1524,8 +1523,7 @@ nsFrameManager::ReResolveStyleContext(nsPresContext    *aPresContext,
           localContent->IsContentOfType(nsIContent::eELEMENT)) {
         // Check for new :after content, but only if the frame is the
         // first-in-flow.
-        nsIFrame* nextInFlow = nsnull;
-        aFrame->GetNextInFlow(&nextInFlow);
+        nsIFrame* nextInFlow = aFrame->GetNextInFlow();
 
         if (!nextInFlow) {
           // Getting the :after frame is more expensive than getting the pseudo
@@ -1623,13 +1621,7 @@ nsFrameManager::ComputeStyleChangeFor(nsIFrame          *aFrame,
   nsIFrame* frame = aFrame;
   nsIFrame* frame2 = aFrame;
 
-#ifdef DEBUG
-  {
-    nsIFrame* prevInFlow;
-    frame->GetPrevInFlow(&prevInFlow);
-    NS_ASSERTION(!prevInFlow, "must start with the first in flow");
-  }
-#endif
+  NS_ASSERTION(!frame->GetPrevInFlow(), "must start with the first in flow");
 
   // We want to start with this frame and walk all its next-in-flows,
   // as well as all its special siblings and their next-in-flows,
@@ -1650,15 +1642,12 @@ nsFrameManager::ComputeStyleChangeFor(nsIFrame          *aFrame,
         // If it's going to cause a framechange, then don't bother
         // with the continuations or special siblings since they'll be
         // clobbered by the frame reconstruct anyway.
-#ifdef NS_DEBUG
-        nsIFrame* prevInFlow;
-        frame->GetPrevInFlow(&prevInFlow);
-        NS_ASSERTION(!prevInFlow, "continuing frame had more severe impact than first-in-flow");
-#endif
+        NS_ASSERTION(!frame->GetPrevInFlow(),
+                     "continuing frame had more severe impact than first-in-flow");
         return topLevelChange;
       }
 
-      frame->GetNextInFlow(&frame);
+      frame = frame->GetNextInFlow();
     } while (frame);
 
     // Might we have special siblings?
diff --git a/mozilla/layout/html/base/src/nsHTMLContainerFrame.cpp b/mozilla/layout/html/base/src/nsHTMLContainerFrame.cpp
index cd1371dfc23..db2d194acee 100644
--- a/mozilla/layout/html/base/src/nsHTMLContainerFrame.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLContainerFrame.cpp
@@ -248,7 +248,7 @@ HasTextFrameDescendant(nsPresContext* aPresContext, nsIFrame* aParent)
 static PRBool 
 HasTextFrameDescendantOrInFlow(nsPresContext* aPresContext, nsIFrame* aFrame)
 {
-  for (nsIFrame *f = aFrame->GetFirstInFlow(); f; f->GetNextInFlow(&f)) {
+  for (nsIFrame *f = aFrame->GetFirstInFlow(); f; f = f->GetNextInFlow()) {
     if (HasTextFrameDescendant(aPresContext, f))
       return PR_TRUE;
   }
@@ -311,8 +311,7 @@ nsHTMLContainerFrame::CreateNextInFlow(nsPresContext* aPresContext,
 {
   aNextInFlowResult = nsnull;
 
-  nsIFrame* nextInFlow;
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aFrame->GetNextInFlow();
   if (nsnull == nextInFlow) {
     // Create a continuation frame for the child frame and insert it
     // into our lines child list.
diff --git a/mozilla/layout/html/base/src/nsHTMLReflowState.cpp b/mozilla/layout/html/base/src/nsHTMLReflowState.cpp
index fe52fdb8ff4..065afb927af 100644
--- a/mozilla/layout/html/base/src/nsHTMLReflowState.cpp
+++ b/mozilla/layout/html/base/src/nsHTMLReflowState.cpp
@@ -1384,8 +1384,7 @@ CalcQuirkContainingBlockHeight(const nsHTMLReflowState& aReflowState)
       }
     }
     else if (nsLayoutAtoms::pageContentFrame == frameType) {
-      nsIFrame* prevInFlow;
-      rs->frame->GetPrevInFlow(&prevInFlow);
+      nsIFrame* prevInFlow = rs->frame->GetPrevInFlow();
       // only use the page content frame for a height basis if it is the first in flow
       if (prevInFlow) 
         break;
diff --git a/mozilla/layout/html/base/src/nsImageFrame.cpp b/mozilla/layout/html/base/src/nsImageFrame.cpp
index 110484e17e9..3c48bb1fc96 100644
--- a/mozilla/layout/html/base/src/nsImageFrame.cpp
+++ b/mozilla/layout/html/base/src/nsImageFrame.cpp
@@ -933,7 +933,7 @@ nsImageFrame::GetContinuationOffset(nscoord* aWidth) const
   }
 
   if (mPrevInFlow) {
-    for (nsIFrame* prevInFlow = mPrevInFlow ; prevInFlow; prevInFlow->GetPrevInFlow(&prevInFlow)) {
+    for (nsIFrame* prevInFlow = mPrevInFlow ; prevInFlow; prevInFlow = prevInFlow->GetPrevInFlow()) {
       nsRect rect = prevInFlow->GetRect();
       if (aWidth) {
         *aWidth = rect.width;
@@ -1019,12 +1019,7 @@ nsImageFrame::Reflow(nsPresContext*          aPresContext,
   aMetrics.descent = 0;
 
   if (aMetrics.mComputeMEW) {
-    // If we have a percentage based width, then our MEW is 0
-    if (eStyleUnit_Percent == aReflowState.mStylePosition->mWidth.GetUnit()) {
-      aMetrics.mMaxElementWidth = 0;
-    } else {
-      aMetrics.mMaxElementWidth = aMetrics.width;
-    }
+    aMetrics.SetMEWToActualWidth(aReflowState.mStylePosition->mWidth.GetUnit());
   }
   
   if (aMetrics.mFlags & NS_REFLOW_CALC_MAX_WIDTH) {
diff --git a/mozilla/layout/html/base/src/nsInlineFrame.cpp b/mozilla/layout/html/base/src/nsInlineFrame.cpp
index 1de294c267e..230abed746e 100644
--- a/mozilla/layout/html/base/src/nsInlineFrame.cpp
+++ b/mozilla/layout/html/base/src/nsInlineFrame.cpp
@@ -261,8 +261,7 @@ nsInlineFrame::RemoveFrame(nsPresContext* aPresContext,
       // When the parent is an inline frame we have a simple task - just
       // remove the frame from its parents list and generate a reflow
       // command.
-      nsIFrame* oldFrameNextInFlow;
-      aOldFrame->GetNextInFlow(&oldFrameNextInFlow);
+      nsIFrame* oldFrameNextInFlow = aOldFrame->GetNextInFlow();
       parent->mFrames.DestroyFrame(aPresContext, aOldFrame);
       aOldFrame = oldFrameNextInFlow;
       if (aOldFrame) {
@@ -514,8 +513,7 @@ nsInlineFrame::ReflowFrames(nsPresContext* aPresContext,
       // its parent frame pointer, too. Otherwise, if we reflow frame and it's
       // complete we'll fail when deleting its next-in-flow which is no longer
       // needed. This scenario doesn't happen often, but it can happen
-      nsIFrame* nextInFlow;
-      frame->GetNextInFlow(&nextInFlow);
+      nsIFrame* nextInFlow = frame->GetNextInFlow();
       while (nextInFlow) {
         // Since we only do lazy setting of parent pointers for the frame's
         // initial reflow, this frame can't have a next-in-flow. That means
@@ -523,7 +521,7 @@ nsInlineFrame::ReflowFrames(nsPresContext* aPresContext,
         // not, then something is wrong
         NS_ASSERTION(mFrames.ContainsFrame(nextInFlow), "unexpected flow");
         nextInFlow->SetParent(this);
-        nextInFlow->GetNextInFlow(&nextInFlow);
+        nextInFlow = nextInFlow->GetNextInFlow();
       }
     }
     rv = ReflowInlineFrame(aPresContext, aReflowState, irs, frame, aStatus);
diff --git a/mozilla/layout/html/base/src/nsLineLayout.cpp b/mozilla/layout/html/base/src/nsLineLayout.cpp
index 03e94b4c984..d0a8e470526 100644
--- a/mozilla/layout/html/base/src/nsLineLayout.cpp
+++ b/mozilla/layout/html/base/src/nsLineLayout.cpp
@@ -230,8 +230,7 @@ PRBool nsLineLayout::AllocateDeque()
 inline PRBool
 HasPrevInFlow(nsIFrame *aFrame)
 {
-  nsIFrame *prevInFlow;
-  aFrame->GetPrevInFlow(&prevInFlow);
+  nsIFrame *prevInFlow = aFrame->GetPrevInFlow();
   return prevInFlow != nsnull;
 }
 
@@ -1151,8 +1150,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
     // the frame is going to get reflowed again (and may end up wanting
     // a next-in-flow where it ends up).
     if (NS_FRAME_IS_COMPLETE(aReflowStatus)) {
-      nsIFrame* kidNextInFlow;
-      aFrame->GetNextInFlow(&kidNextInFlow);
+      nsIFrame* kidNextInFlow = aFrame->GetNextInFlow();
       if (nsnull != kidNextInFlow) {
         // Remove all of the childs next-in-flows. Make sure that we ask
         // the right parent to do the removal (it's possible that the
@@ -1203,8 +1201,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
       PRInt32 newEnd;
       aFrame->GetOffsets(start, newEnd);
       if (newEnd != end) {
-        nsIFrame* nextInFlow;
-        aFrame->GetNextInFlow(&nextInFlow);
+        nsIFrame* nextInFlow = aFrame->GetNextInFlow();
         if (nextInFlow) {
           nextInFlow->GetOffsets(start, end);
           nextInFlow->AdjustOffsetsForBidi(newEnd, end);
@@ -1387,11 +1384,9 @@ nsLineLayout::CanPlaceFrame(PerFrameData* pfd,
   // If this is a piece of text inside a letter frame...
   if (pfd->GetFlag(PFD_ISNONEMPTYTEXTFRAME)) {
     if (psd->mFrame && psd->mFrame->GetFlag(PFD_ISLETTERFRAME)) {
-      nsIFrame* prevInFlow;
-      psd->mFrame->mFrame->GetPrevInFlow(&prevInFlow);
+      nsIFrame* prevInFlow = psd->mFrame->mFrame->GetPrevInFlow();
       if (prevInFlow) {
-        nsIFrame* prevPrevInFlow;
-        prevInFlow->GetPrevInFlow(&prevPrevInFlow);
+        nsIFrame* prevPrevInFlow = prevInFlow->GetPrevInFlow();
         if (!prevPrevInFlow) {
           // And it's the first continuation of the letter frame...
           // Then make sure that the text fits
@@ -1402,11 +1397,9 @@ nsLineLayout::CanPlaceFrame(PerFrameData* pfd,
   }
   else if (pfd->GetFlag(PFD_ISLETTERFRAME)) {
     // If this is the first continuation of the letter frame...
-    nsIFrame* prevInFlow;
-    pfd->mFrame->GetPrevInFlow(&prevInFlow);
+    nsIFrame* prevInFlow = pfd->mFrame->GetPrevInFlow();
     if (prevInFlow) {
-      nsIFrame* prevPrevInFlow;
-      prevInFlow->GetPrevInFlow(&prevPrevInFlow);
+      nsIFrame* prevPrevInFlow = prevInFlow->GetPrevInFlow();
       if (!prevPrevInFlow) {
         return PR_TRUE;
       }
@@ -1929,10 +1922,8 @@ nsLineLayout::VerticalAlignFrames(PerSpanData* psd)
   // - it has a prev-in-flow
   // - it has no next in flow
   // - it's zero sized
-  nsIFrame* spanNextInFlow;
-  spanFrame->GetNextInFlow(&spanNextInFlow);
-  nsIFrame* spanPrevInFlow;
-  spanFrame->GetPrevInFlow(&spanPrevInFlow);
+  nsIFrame* spanNextInFlow = spanFrame->GetNextInFlow();
+  nsIFrame* spanPrevInFlow = spanFrame->GetPrevInFlow();
   PRBool emptyContinuation = spanPrevInFlow && !spanNextInFlow &&
     (0 == spanFramePFD->mBounds.width) && (0 == spanFramePFD->mBounds.height);
 
diff --git a/mozilla/layout/html/base/src/nsPageContentFrame.cpp b/mozilla/layout/html/base/src/nsPageContentFrame.cpp
index 1e76bba764a..b33c5fef664 100644
--- a/mozilla/layout/html/base/src/nsPageContentFrame.cpp
+++ b/mozilla/layout/html/base/src/nsPageContentFrame.cpp
@@ -117,15 +117,8 @@ NS_IMETHODIMP nsPageContentFrame::Reflow(nsPresContext*   aPresContext,
       // Place and size the child
       FinishReflowChild(frame, aPresContext, &kidReflowState, aDesiredSize, 0, 0, 0);
 
-#ifdef NS_DEBUG
-      // Is the frame complete?
-      if (NS_FRAME_IS_COMPLETE(aStatus)) {
-        nsIFrame* childNextInFlow;
-
-        frame->GetNextInFlow(&childNextInFlow);
-        NS_ASSERTION(nsnull == childNextInFlow, "bad child flow list");
-      }
-#endif
+      NS_ASSERTION(!NS_FRAME_IS_COMPLETE(aStatus) ||
+                   !frame->GetNextInFlow(), "bad child flow list");
 
 #ifdef DEBUG_PRINTING
       nsRect r = frame->GetRect();
diff --git a/mozilla/layout/html/base/src/nsPageFrame.cpp b/mozilla/layout/html/base/src/nsPageFrame.cpp
index 14941e08a23..97181eb3dd4 100644
--- a/mozilla/layout/html/base/src/nsPageFrame.cpp
+++ b/mozilla/layout/html/base/src/nsPageFrame.cpp
@@ -221,15 +221,8 @@ NS_IMETHODIMP nsPageFrame::Reflow(nsPresContext*          aPresContext,
         view->GetViewManager()->SetViewChildClipRegion(view, &region);
       }
 
-#ifdef NS_DEBUG
-      // Is the frame complete?
-      if (NS_FRAME_IS_COMPLETE(aStatus)) {
-        nsIFrame* childNextInFlow;
-
-        frame->GetNextInFlow(&childNextInFlow);
-        NS_ASSERTION(nsnull == childNextInFlow, "bad child flow list");
-      }
-#endif
+      NS_ASSERTION(!NS_FRAME_IS_COMPLETE(aStatus) ||
+                   !frame->GetNextInFlow(), "bad child flow list");
     }
     PR_PL(("PageFrame::Reflow %p ", this));
     PR_PL(("[%d,%d][%d,%d]\n", aDesiredSize.width, aDesiredSize.height, aReflowState.availableWidth, aReflowState.availableHeight));
diff --git a/mozilla/layout/html/base/src/nsSimplePageSequence.cpp b/mozilla/layout/html/base/src/nsSimplePageSequence.cpp
index 1dcab054be3..10af040c3a7 100644
--- a/mozilla/layout/html/base/src/nsSimplePageSequence.cpp
+++ b/mozilla/layout/html/base/src/nsSimplePageSequence.cpp
@@ -428,8 +428,7 @@ nsSimplePageSequenceFrame::Reflow(nsPresContext*          aPresContext,
       y += deadSpaceGap;
 
       // Is the page complete?
-      nsIFrame* kidNextInFlow;
-      kidFrame->GetNextInFlow(&kidNextInFlow);
+      nsIFrame* kidNextInFlow = kidFrame->GetNextInFlow();
 
       if (NS_FRAME_IS_COMPLETE(status)) {
         NS_ASSERTION(nsnull == kidNextInFlow, "bad child flow list");
diff --git a/mozilla/layout/html/base/src/nsSplittableFrame.cpp b/mozilla/layout/html/base/src/nsSplittableFrame.cpp
index 10cf15ee0e1..c13d5fef751 100644
--- a/mozilla/layout/html/base/src/nsSplittableFrame.cpp
+++ b/mozilla/layout/html/base/src/nsSplittableFrame.cpp
@@ -78,10 +78,9 @@ nsSplittableFrame::IsSplittable(nsSplittableType& aIsSplittable) const
   return NS_OK;
 }
 
-NS_METHOD nsSplittableFrame::GetPrevInFlow(nsIFrame** aPrevInFlow) const
+nsIFrame* nsSplittableFrame::GetPrevInFlow() const
 {
-  *aPrevInFlow = mPrevInFlow;
-  return NS_OK;
+  return mPrevInFlow;
 }
 
 NS_METHOD nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
@@ -90,10 +89,9 @@ NS_METHOD nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
   return NS_OK;
 }
 
-NS_METHOD nsSplittableFrame::GetNextInFlow(nsIFrame** aNextInFlow) const
+nsIFrame* nsSplittableFrame::GetNextInFlow() const
 {
-  *aNextInFlow = mNextInFlow;
-  return NS_OK;
+  return mNextInFlow;
 }
 
 NS_METHOD nsSplittableFrame::SetNextInFlow(nsIFrame* aFrame)
@@ -126,11 +124,8 @@ nsIFrame* nsSplittableFrame::GetLastInFlow() const
 void
 nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
 {
-  nsIFrame* prevInFlow;
-  nsIFrame* nextInFlow;
-
-  aFrame->GetPrevInFlow(&prevInFlow);
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
+  nsIFrame* nextInFlow = aFrame->GetNextInFlow();
 
   if (prevInFlow) {
     prevInFlow->SetNextInFlow(nextInFlow);
@@ -148,25 +143,13 @@ nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
 void
 nsSplittableFrame::BreakFromPrevFlow(nsIFrame* aFrame)
 {
-  nsIFrame* prevInFlow;
-
-  aFrame->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
   if (prevInFlow) {
     prevInFlow->SetNextInFlow(nsnull);
     aFrame->SetPrevInFlow(nsnull);
   }
 }
 
-nsIFrame * nsSplittableFrame::GetPrevInFlow() 
-{
-  return mPrevInFlow;
-}
-
-nsIFrame * nsSplittableFrame::GetNextInFlow()
-{
-   return mNextInFlow;
-} 
-
 #ifdef DEBUG
 void
 nsSplittableFrame::DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, PRInt32 aIndent, PRBool aIncludeStyleData)
diff --git a/mozilla/layout/html/base/src/nsSplittableFrame.h b/mozilla/layout/html/base/src/nsSplittableFrame.h
index 801ba0f64ee..769344d1887 100644
--- a/mozilla/layout/html/base/src/nsSplittableFrame.h
+++ b/mozilla/layout/html/base/src/nsSplittableFrame.h
@@ -54,9 +54,9 @@ public:
   NS_IMETHOD Destroy(nsPresContext* aPresContext);
 
   // Flow member functions.
-  NS_IMETHOD  GetPrevInFlow(nsIFrame** aPrevInFlow) const;
+  virtual nsIFrame* GetPrevInFlow() const;
   NS_IMETHOD  SetPrevInFlow(nsIFrame*);
-  NS_IMETHOD  GetNextInFlow(nsIFrame** aNextInFlow) const;
+  virtual nsIFrame*  GetNextInFlow() const;
   NS_IMETHOD  SetNextInFlow(nsIFrame*);
 
   /**
@@ -76,9 +76,6 @@ public:
   // Detach from previous frame in flow
   static void BreakFromPrevFlow(nsIFrame* aFrame);
 
-  nsIFrame*   GetPrevInFlow();
-  nsIFrame*   GetNextInFlow();
-
 protected:
 #ifdef DEBUG
   virtual void DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, PRInt32 aIndent, PRBool aIncludeStyleData);
diff --git a/mozilla/layout/html/base/src/nsTextFrame.cpp b/mozilla/layout/html/base/src/nsTextFrame.cpp
index e44c76e6829..8bad9682b82 100644
--- a/mozilla/layout/html/base/src/nsTextFrame.cpp
+++ b/mozilla/layout/html/base/src/nsTextFrame.cpp
@@ -404,9 +404,8 @@ public:
                                   nsIContent*     aChild,
                                   PRBool          aAppend);
 
-  NS_IMETHOD GetNextInFlow(nsIFrame** aNextInFlow) const {
-    *aNextInFlow = mNextInFlow;
-    return NS_OK;
+  virtual nsIFrame* GetNextInFlow() const {
+    return mNextInFlow;
   }
   NS_IMETHOD SetNextInFlow(nsIFrame* aNextInFlow) {
     mNextInFlow = aNextInFlow;
@@ -843,9 +842,8 @@ public:
 
   NS_IMETHOD Destroy(nsPresContext* aPresContext);
 
-  NS_IMETHOD GetPrevInFlow(nsIFrame** aPrevInFlow) const {
-    *aPrevInFlow = mPrevInFlow;
-    return NS_OK;
+  virtual nsIFrame* GetPrevInFlow() const {
+    return mPrevInFlow;
   }
   NS_IMETHOD SetPrevInFlow(nsIFrame* aPrevInFlow) {
     mPrevInFlow = aPrevInFlow;
@@ -925,7 +923,7 @@ nsContinuingTextFrame::GetFirstInFlow() const
                                      NS_STATIC_CAST(const nsIFrame*, this));
   do {
     firstInFlow = previous;
-    firstInFlow->GetPrevInFlow(&previous);
+    previous = firstInFlow->GetPrevInFlow();
   } while (previous);
   return firstInFlow;
 }
@@ -3568,7 +3566,6 @@ nsTextFrame::SetSelected(nsPresContext* aPresContext,
                          PRBool aSelected,
                          nsSpread aSpread)
 {
-  nsresult result;
   if (aSelected && ParentDisablesSelection())
     return NS_OK;
 
@@ -3685,20 +3682,15 @@ nsTextFrame::SetSelected(nsPresContext* aPresContext,
   }
   if (aSpread == eSpreadDown)
   {
-    nsIFrame *frame;
-    GetPrevInFlow(&frame);
+    nsIFrame* frame = GetPrevInFlow();
     while(frame){
       frame->SetSelected(aPresContext, aRange,aSelected,eSpreadNone);
-      result = frame->GetPrevInFlow(&frame);
-      if (NS_FAILED(result))
-        break;
+      frame = frame->GetPrevInFlow();
     }
-    GetNextInFlow(&frame);
+    frame = GetNextInFlow();
     while (frame){
       frame->SetSelected(aPresContext, aRange,aSelected,eSpreadNone);
-      result = frame->GetNextInFlow(&frame);
-      if (NS_FAILED(result))
-        break;
+      frame = frame->GetNextInFlow();
     }
 #ifdef IBMBIDI
     if ((mState & NS_FRAME_IS_BIDI) &&
@@ -3831,7 +3823,6 @@ nsTextFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset,
 {
   if (nsnull == outChildFrame)
     return NS_ERROR_NULL_POINTER;
-  nsresult result;
   PRInt32 contentOffset = inContentOffset;
   
   if (contentOffset != -1) //-1 signified the end of the current content
@@ -3840,8 +3831,7 @@ nsTextFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset,
   if ((contentOffset > mContentLength) || ((contentOffset == mContentLength) && inHint) )
   {
     //this is not the frame we are looking for.
-    nsIFrame *nextInFlow;
-    GetNextInFlow(&nextInFlow);
+    nsIFrame* nextInFlow = GetNextInFlow();
     if (nextInFlow)
     {
       return nextInFlow->GetChildFrameContainingOffset(inContentOffset, inHint, outFrameContentOffset, outChildFrame);
@@ -3873,12 +3863,12 @@ nsTextFrame::GetChildFrameContainingOffset(PRInt32 inContentOffset,
 
   if (inContentOffset < mContentOffset) //could happen with floats!
   {
-    result = GetPrevInFlow(outChildFrame);
-    if (NS_SUCCEEDED(result) && *outChildFrame)
+    *outChildFrame = GetPrevInFlow();
+    if (*outChildFrame)
       return (*outChildFrame)->GetChildFrameContainingOffset(inContentOffset, inHint,
         outFrameContentOffset,outChildFrame);
     else
-      return result;
+      return NS_OK; //this can't be the right thing to do?
   }
   
   *outFrameContentOffset = contentOffset;
@@ -3915,7 +3905,7 @@ nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos)
     }
     else
 #endif
-    GetNextInFlow(&nextInFlow);
+    nextInFlow = GetNextInFlow();
     if (!nextInFlow){
       NS_ASSERTION(PR_FALSE,"nsTextFrame::PeekOffset no more flow \n");
       return NS_ERROR_INVALID_ARG;
@@ -4040,7 +4030,7 @@ nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos)
 
           if (i <0){
             found = PR_FALSE;
-            GetPrevInFlow(&frameUsed);
+            frameUsed = GetPrevInFlow();
             start = mContentOffset;
             aPos->mContentOffset = start;//in case next call fails we stop at this offset
           }
@@ -4095,7 +4085,7 @@ nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos)
   */
           if (i > mContentLength){
             found = PR_FALSE;
-            GetNextInFlow(&frameUsed);
+            frameUsed = GetNextInFlow();
             start = mContentOffset + mContentLength;
             aPos->mContentOffset = start;//in case next call fails we stop at this offset
           }
@@ -4250,7 +4240,7 @@ nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos)
           } 
 
   TryNextFrame:        
-          GetNextInFlow(&frameUsed);
+          frameUsed = GetNextInFlow();
           start = 0;
         }
       }
@@ -4398,7 +4388,7 @@ nsTextFrame::CheckVisibility(nsPresContext* aContext, PRInt32 aStartIndex, PRInt
     rv = NS_OK;
     while (!aFinished && nextInFlow && NS_SUCCEEDED(rv) && !*_retval) //while we havent found anything visible
     {
-      rv = nextInFlow->GetNextInFlow(&nextInFlow);
+      nextInFlow = nextInFlow->GetNextInFlow();
       if (nextInFlow)
       {
         rv = nextInFlow->CheckVisibility(aContext,aStartIndex,aEndIndex,PR_FALSE,aFinished,_retval);
@@ -5186,9 +5176,7 @@ nsTextFrame::Reflow(nsPresContext*          aPresContext,
 
   // Get starting offset into the content
   PRInt32 startingOffset = 0;
-  nsIFrame* prevInFlow;
-
-  GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = GetPrevInFlow();
   if (nsnull != prevInFlow) {
     nsTextFrame* prev = (nsTextFrame*)prevInFlow;
     startingOffset = prev->mContentOffset + prev->mContentLength;
@@ -5912,8 +5900,7 @@ nsTextFrame::List(nsPresContext* aPresContext, FILE* out, PRInt32 aIndent) const
   if (nsnull != mNextSibling) {
     fprintf(out, " next=%p", NS_STATIC_CAST(void*, mNextSibling));
   }
-  nsIFrame* prevInFlow;
-  GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = GetPrevInFlow();
   if (nsnull != prevInFlow) {
     fprintf(out, " prev-in-flow=%p", NS_STATIC_CAST(void*, prevInFlow));
   }
diff --git a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
index 255c49c8612..82a7615f02f 100644
--- a/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/html/style/src/nsCSSFrameConstructor.cpp
@@ -450,8 +450,7 @@ GetLastSpecialSibling(nsFrameManager* aFrameManager, nsIFrame* aFrame)
 static nsIFrame*
 GetNifOrSpecialSibling(nsFrameManager *aFrameManager, nsIFrame *aFrame)
 {
-  nsIFrame *result;
-  aFrame->GetNextInFlow(&result);
+  nsIFrame *result = aFrame->GetNextInFlow();
   if (result)
     return result;
 
@@ -466,17 +465,14 @@ SetFrameIsSpecial(nsFrameManager* aFrameManager, nsIFrame* aFrame, nsIFrame* aSp
   NS_PRECONDITION(aFrameManager && aFrame, "bad args!");
 
   // Mark the frame and all of its siblings as "special".
-  for (nsIFrame* frame = aFrame; frame != nsnull; frame->GetNextInFlow(&frame)) {
+  for (nsIFrame* frame = aFrame; frame != nsnull; frame = frame->GetNextInFlow()) {
     frame->AddStateBits(NS_FRAME_IS_SPECIAL);
   }
 
   if (aSpecialSibling) {
-#ifdef DEBUG
     // We should be the first-in-flow
-    nsIFrame* prev;
-    aFrame->GetPrevInFlow(&prev);
-    NS_ASSERTION(! prev, "assigning special sibling to other than first-in-flow!");
-#endif
+    NS_ASSERTION(!aFrame->GetPrevInFlow(),
+                 "assigning special sibling to other than first-in-flow!");
 
     // Store the "special sibling" (if we were given one) with the
     // first frame in the flow.
@@ -7810,12 +7806,9 @@ FindNextAnonymousSibling(nsIPresShell* aPresShell,
     nsIFrame* nextSibling;
     aPresShell->GetPrimaryFrameFor(child, &nextSibling);
     if (nextSibling) {
-#ifdef DEBUG
       // The primary frame should never be a continuation
-      nsIFrame* prevInFlow;
-      nextSibling->GetPrevInFlow(&prevInFlow);
-      NS_ASSERTION(!prevInFlow, "primary frame is a continuation!?");
-#endif
+      NS_ASSERTION(!nextSibling->GetPrevInFlow(),
+                   "primary frame is a continuation!?");
 
       // If the frame is out-of-flow, GPFF() will have returned the
       // out-of-flow frame; we want the placeholder.
@@ -7996,12 +7989,9 @@ nsCSSFrameConstructor::FindNextSibling(nsIPresShell*     aPresShell,
     aPresShell->GetPrimaryFrameFor(nsCOMPtr<nsIContent>(*iter), &nextSibling);
 
     if (nextSibling) {
-#ifdef DEBUG
       // The frame primary frame should never be a continuation
-      nsIFrame* prevInFlow;
-      nextSibling->GetPrevInFlow(&prevInFlow);
-      NS_ASSERTION(!prevInFlow, "primary frame is a continuation!?");
-#endif
+      NS_ASSERTION(!nextSibling->GetPrevInFlow(),
+                   "primary frame is a continuation!?");
 
       // If the frame is out-of-flow, GPFF() will have returned the
       // out-of-flow frame; we want the placeholder.
@@ -9298,7 +9288,7 @@ DeletingFrameSubtree(nsPresContext*  aPresContext,
       // recursing over a subtree, because those continuing frames should be
       // found as part of the walk over the top-most frame's continuing frames.
       // Walking them again will make this an N^2/2 algorithm
-      aFrame->GetNextInFlow(&aFrame);
+      aFrame = aFrame->GetNextInFlow();
     } while (aFrame);
 
     // Now destroy any frames that have been enqueued for destruction.
@@ -10691,8 +10681,7 @@ nsCSSFrameConstructor::CreateContinuingTableFrame(nsIPresShell* aPresShell,
       if ((NS_STYLE_DISPLAY_TABLE_HEADER_GROUP == display->mDisplay) ||
           (NS_STYLE_DISPLAY_TABLE_FOOTER_GROUP == display->mDisplay)) {
         // If the row group has was continued, then don't replicate it
-        nsIFrame* rgNextInFlow;
-        rowGroupFrame->GetNextInFlow(&rgNextInFlow);
+        nsIFrame* rgNextInFlow = rowGroupFrame->GetNextInFlow();
         if (rgNextInFlow) {
           ((nsTableRowGroupFrame*)rowGroupFrame)->SetRepeatable(PR_FALSE);
         }
@@ -10746,9 +10735,7 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsPresContext* aPresContext,
   nsStyleContext*            styleContext = aFrame->GetStyleContext();
   nsIFrame*                  newFrame = nsnull;
   nsresult                   rv = NS_OK;
-  nsIFrame*                  nextInFlow = nsnull;
-
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame*                  nextInFlow = aFrame->GetNextInFlow();
 
   // Use the frame type to determine what type of frame to create
   nsIAtom* frameType = aFrame->GetType();
@@ -10944,8 +10931,7 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsPresContext* aPresContext,
     return NS_ERROR_UNEXPECTED;
   }
 
-  nsIFrame* prevPage;
-  pageFrame->GetPrevInFlow(&prevPage);
+  nsIFrame* prevPage = pageFrame->GetPrevInFlow();
   if (!prevPage) {
     return NS_OK;
   }
@@ -11877,8 +11863,7 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
         // need to be pulled out of the line-frame and become children
         // of the block.
         nsIFrame* nextSibling = aPrevSibling->GetNextSibling();
-        nsIFrame* nextLineFrame;
-        prevSiblingParent->GetNextInFlow(&nextLineFrame);
+        nsIFrame* nextLineFrame = prevSiblingParent->GetNextInFlow();
         if (nextSibling || nextLineFrame) {
           // Oy. We have work to do. Create a list of the new frames
           // that are going into the block by stripping them away from
@@ -11891,7 +11876,7 @@ nsCSSFrameConstructor::InsertFirstLineFrames(
 
           nsLineFrame* nextLineFrame = (nsLineFrame*) lineFrame;
           for (;;) {
-            nextLineFrame->GetNextInFlow(&nextLineFrame);
+            nextLineFrame = nextLineFrame->GetNextInFlow();
             if (!nextLineFrame) {
               break;
             }
@@ -12324,8 +12309,7 @@ nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames(
 
   // Destroy the old text frame's continuations (the old text frame
   // will be destroyed when its letter frame is destroyed).
-  nsIFrame* nextTextFrame;
-  textFrame->GetNextInFlow(&nextTextFrame);
+  nsIFrame* nextTextFrame = textFrame->GetNextInFlow();
   if (nextTextFrame) {
     nsIFrame* nextTextParent = nextTextFrame->GetParent();
     if (nextTextParent) {
@@ -13268,8 +13252,7 @@ nsCSSFrameConstructor::SplitToContainingBlock(nsPresContext* aPresContext,
 
   // If we have a continuation frame, then we need to break the
   // continuation.
-  nsIFrame* nextInFlow;
-  aFrame->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aFrame->GetNextInFlow();
   if (nextInFlow) {
     aFrame->SetNextInFlow(nsnull);
     nextInFlow->SetPrevInFlow(nsnull);
diff --git a/mozilla/layout/html/style/src/nsCSSRendering.cpp b/mozilla/layout/html/style/src/nsCSSRendering.cpp
index eeae52f1fc9..60ff6f6bd12 100644
--- a/mozilla/layout/html/style/src/nsCSSRendering.cpp
+++ b/mozilla/layout/html/style/src/nsCSSRendering.cpp
@@ -145,8 +145,7 @@ protected:
   {
     NS_PRECONDITION(aFrame, "Need a frame");
 
-    nsIFrame *prevInFlow = nsnull;
-    aFrame->GetPrevInFlow(&prevInFlow);
+    nsIFrame *prevInFlow = aFrame->GetPrevInFlow();
 
     if (!prevInFlow || mFrame != prevInFlow) {
       // Ok, we've got the wrong frame.  We have to start from scratch.
@@ -163,18 +162,17 @@ protected:
   }
 
   void Init(nsIFrame* aFrame)
-  {
-    nsIFrame* inlineFrame;
+  {    
     // Start with the previous flow frame as our continuation point
     // is the total of the widths of the previous frames.
-    aFrame->GetPrevInFlow(&inlineFrame);
+    nsIFrame* inlineFrame = aFrame->GetPrevInFlow();
 
     while (inlineFrame) {
       nsRect rect = inlineFrame->GetRect();
       mContinuationPoint += rect.width;
       mUnbrokenWidth += rect.width;
       mBoundingBox.UnionRect(mBoundingBox, rect);
-      inlineFrame->GetPrevInFlow(&inlineFrame);
+      inlineFrame = inlineFrame->GetPrevInFlow();
     }
 
     // Next add this frame and subsequent frames to the bounding box and
@@ -184,7 +182,7 @@ protected:
       nsRect rect = inlineFrame->GetRect();
       mUnbrokenWidth += rect.width;
       mBoundingBox.UnionRect(mBoundingBox, rect);
-      inlineFrame->GetNextInFlow(&inlineFrame);
+      inlineFrame = inlineFrame->GetNextInFlow();
     }
 
     mFrame = aFrame;
diff --git a/mozilla/layout/html/style/src/nsFrameContentIterator.cpp b/mozilla/layout/html/style/src/nsFrameContentIterator.cpp
index 31e0f8c46bd..18419911c87 100644
--- a/mozilla/layout/html/style/src/nsFrameContentIterator.cpp
+++ b/mozilla/layout/html/style/src/nsFrameContentIterator.cpp
@@ -122,8 +122,7 @@ GetNextChildFrame(nsPresContext* aPresContext, nsIFrame* aFrame)
   // If there's no next sibling, then check if the parent frame
   // has a next-in-flow and look there
   if (!nextSibling) {
-    nsIFrame* parent;
-    aFrame->GetParent()->GetNextInFlow(&parent);
+    nsIFrame* parent = aFrame->GetParent()->GetNextInFlow();
 
     if (parent) {
       nextSibling = parent->GetFirstChild(nsnull);
@@ -184,7 +183,7 @@ GetPrevChildFrame(nsPresContext* aPresContext, nsIFrame* aFrame)
   // If there's no previous sibling, then check if the parent frame
   // has a prev-in-flow and look there
   if (!prevSibling) {
-    parent->GetPrevInFlow(&parent);
+    parent = parent->GetPrevInFlow();
 
     if (parent) {
       firstChild = parent->GetFirstChild(nsnull);
@@ -195,8 +194,7 @@ GetPrevChildFrame(nsPresContext* aPresContext, nsIFrame* aFrame)
   
   // Get the first-in-flow
   while (PR_TRUE) {
-    nsIFrame* prevInFlow;
-    prevSibling->GetPrevInFlow(&prevInFlow);
+    nsIFrame* prevInFlow = prevSibling->GetPrevInFlow();
     if (prevInFlow) {
       prevSibling = prevInFlow;
     } else {
diff --git a/mozilla/layout/html/table/src/BasicTableLayoutStrategy.cpp b/mozilla/layout/html/table/src/BasicTableLayoutStrategy.cpp
index 0d58e2018e8..8f630ddccaa 100644
--- a/mozilla/layout/html/table/src/BasicTableLayoutStrategy.cpp
+++ b/mozilla/layout/html/table/src/BasicTableLayoutStrategy.cpp
@@ -170,11 +170,8 @@ PRBool BasicTableLayoutStrategy::Initialize(const nsHTMLReflowState& aReflowStat
 
 void BasicTableLayoutStrategy::ContinuingFrameCheck()
 {
-#ifdef NS_DEBUG
-  nsIFrame* tablePIF = nsnull;
-  mTableFrame->GetPrevInFlow(&tablePIF);
-  NS_ASSERTION(!tablePIF, "never ever call me on a continuing frame!");
-#endif
+  NS_ASSERTION(!mTableFrame->GetPrevInFlow(),
+               "never ever call me on a continuing frame!");
 }
 
 PRBool BCW_Wrapup(const nsHTMLReflowState&  aReflowState,
diff --git a/mozilla/layout/html/table/src/nsTableFrame.cpp b/mozilla/layout/html/table/src/nsTableFrame.cpp
index db4af5be795..d595ed3bb28 100644
--- a/mozilla/layout/html/table/src/nsTableFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableFrame.cpp
@@ -1723,8 +1723,7 @@ void
 nsTableFrame::CheckRequestSpecialHeightReflow(const nsHTMLReflowState& aReflowState)
 {
   if (!aReflowState.frame) ABORT0();
-  nsIFrame* prevInFlow;
-  aReflowState.frame->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aReflowState.frame->GetPrevInFlow();
 
   if (!prevInFlow                                             &&   // 1st in flow                                            && // 1st in flow
       ((NS_UNCONSTRAINEDSIZE == aReflowState.mComputedHeight) ||   // no computed height
@@ -3104,8 +3103,7 @@ nsTableFrame::OrderRowGroups(nsVoidArray&           aChildren,
     // Get the next sibling but skip it if it's also the next-in-flow, since
     // a next-in-flow will not be part of the current table.
     while (kidFrame) {
-      nsIFrame* nif;
-      kidFrame->GetNextInFlow(&nif);
+      nsIFrame* nif = kidFrame->GetNextInFlow();
       kidFrame = kidFrame->GetNextSibling();
       if (kidFrame != nif) 
         break;
@@ -3219,8 +3217,7 @@ nsTableFrame::ReflowChildren(nsPresContext*     aPresContext,
         
         // record the next in flow in case it gets destroyed and the row group array
         // needs to be recomputed.
-        nsIFrame* kidNextInFlow;
-        kidFrame->GetNextInFlow(&kidNextInFlow);
+        nsIFrame* kidNextInFlow = kidFrame->GetNextInFlow();
   
         rv = ReflowChild(kidFrame, aPresContext, desiredSize, kidReflowState,
                          aReflowState.x, aReflowState.y, 0, aStatus);
@@ -3243,7 +3240,7 @@ nsTableFrame::ReflowChildren(nsPresContext*     aPresContext,
  
         // Special handling for incomplete children
         if (NS_FRAME_IS_NOT_COMPLETE(aStatus)) {         
-          kidFrame->GetNextInFlow(&kidNextInFlow);
+          kidNextInFlow = kidFrame->GetNextInFlow();
           if (!kidNextInFlow) {
             // The child doesn't have a next-in-flow so create a continuing
             // frame. This hooks the child into the flow
@@ -7487,12 +7484,11 @@ void DumpTableFramesRecur(nsIFrame*       aFrame,
   GetFrameTypeName(fType, fName);
 
   printf("%s%s %p", indent, fName, aFrame);
-  nsIFrame* flowFrame;
-  aFrame->GetPrevInFlow(&flowFrame);
+  nsIFrame* flowFrame = aFrame->GetPrevInFlow();
   if (flowFrame) {
     printf(" pif=%p", flowFrame);
   }
-  aFrame->GetNextInFlow(&flowFrame);
+  flowFrame = aFrame->GetNextInFlow();
   if (flowFrame) {
     printf(" nif=%p", flowFrame);
   }
@@ -7516,15 +7512,15 @@ nsTableFrame::DumpTableFrames(nsIFrame* aFrame)
   nsTableFrame* tableFrame = nsnull;
 
   if (nsLayoutAtoms::tableFrame == aFrame->GetType()) { 
-    tableFrame = (nsTableFrame*)aFrame;
+    tableFrame = NS_STATIC_CAST(nsTableFrame*, aFrame);
   }
   else {
     nsTableFrame::GetTableFrame(aFrame, tableFrame);
   }
-  tableFrame = (nsTableFrame*)tableFrame->GetFirstInFlow();
+  tableFrame = NS_STATIC_CAST(nsTableFrame*, tableFrame->GetFirstInFlow());
   while (tableFrame) {
     DumpTableFramesRecur(tableFrame, 0);
-    tableFrame->GetNextInFlow((nsIFrame**)&tableFrame);
+    tableFrame = NS_STATIC_CAST(nsTableFrame*, tableFrame->GetNextInFlow());
   }
 }
 
@@ -7532,4 +7528,3 @@ nsTableFrame::DumpTableFrames(nsIFrame* aFrame)
 
 
 
-
diff --git a/mozilla/layout/html/table/src/nsTableOuterFrame.cpp b/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
index 22b7f908ea4..9d7ca357618 100644
--- a/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableOuterFrame.cpp
@@ -2116,9 +2116,7 @@ void nsTableOuterFrame::DeleteChildsNextInFlow(nsPresContext* aPresContext,
   if (!aChild) return;
   NS_PRECONDITION(mFrames.ContainsFrame(aChild), "bad geometric parent");
 
-  nsIFrame* nextInFlow;
-   
-  aChild->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aChild->GetNextInFlow();
   if (!nextInFlow) {
     NS_ASSERTION(PR_FALSE, "null next-in-flow");
     return;
@@ -2132,9 +2130,7 @@ void nsTableOuterFrame::DeleteChildsNextInFlow(nsPresContext* aPresContext,
   }
   // If the next-in-flow has a next-in-flow then delete it too (and
   // delete it first).
-  nsIFrame* nextNextInFlow;
-
-  nextInFlow->GetNextInFlow(&nextNextInFlow);
+  nsIFrame* nextNextInFlow = nextInFlow->GetNextInFlow();
   if (nextNextInFlow) {
     parent->DeleteChildsNextInFlow(aPresContext, nextInFlow);
   }
@@ -2159,10 +2155,7 @@ void nsTableOuterFrame::DeleteChildsNextInFlow(nsPresContext* aPresContext,
   // Delete the next-in-flow frame and adjust it's parent's child count
   nextInFlow->Destroy(aPresContext);
 
-#ifdef NS_DEBUG
-  aChild->GetNextInFlow(&nextInFlow);
-  NS_POSTCONDITION(nsnull == nextInFlow, "non null next-in-flow");
-#endif
+  NS_POSTCONDITION(!aChild->GetNextInFlow(), "non null next-in-flow");
 }
 
 nsIAtom*
diff --git a/mozilla/layout/html/table/src/nsTableRowFrame.cpp b/mozilla/layout/html/table/src/nsTableRowFrame.cpp
index 38fc27e42ff..a7b9ce76282 100644
--- a/mozilla/layout/html/table/src/nsTableRowFrame.cpp
+++ b/mozilla/layout/html/table/src/nsTableRowFrame.cpp
@@ -783,7 +783,7 @@ nscoord CalcHeightFromUnpaginatedHeight(nsPresContext*  aPresContext,
   if (firstInFlow->HasUnpaginatedHeight()) {
     height = firstInFlow->GetUnpaginatedHeight(aPresContext);
     for (nsIFrame* prevInFlow = aRow.GetPrevInFlow(); prevInFlow;
-         prevInFlow->GetPrevInFlow(&prevInFlow)) {
+         prevInFlow = prevInFlow->GetPrevInFlow()) {
       height -= prevInFlow->GetSize().height;
     }
   }
@@ -806,8 +806,7 @@ nsTableRowFrame::ReflowChildren(nsPresContext*          aPresContext,
   GET_PIXELS_TO_TWIPS(aPresContext, p2t);
   PRBool borderCollapse = (((nsTableFrame*)aTableFrame.GetFirstInFlow())->IsBorderCollapse());
 
-  nsIFrame* tablePrevInFlow;
-  aTableFrame.GetPrevInFlow(&tablePrevInFlow);
+  nsIFrame* tablePrevInFlow = aTableFrame.GetPrevInFlow();
   PRBool isPaginated = aPresContext->IsPaginated();
 
   nsresult rv = NS_OK;
@@ -899,8 +898,7 @@ nsTableRowFrame::ReflowChildren(nsPresContext*          aPresContext,
         // the cell wants to be bigger than what was available last time or
         // it is a style change reflow or we are printing, then we must reflow the
         // cell. Otherwise we can skip the reflow.
-        nsIFrame* kidNextInFlow;
-        kidFrame->GetNextInFlow(&kidNextInFlow);
+        nsIFrame* kidNextInFlow = kidFrame->GetNextInFlow();
         nsSize cellDesiredSize = cellFrame->GetDesiredSize();
         if ((availCellWidth != cellFrame->GetPriorAvailWidth())       ||
             (cellDesiredSize.width > cellFrame->GetPriorAvailWidth()) ||
@@ -1348,9 +1346,7 @@ nsTableRowFrame::IR_TargetIsChild(nsPresContext*          aPresContext,
   if (mNextInFlow) {
     for (nsIFrame* cell = mFrames.FirstChild(); cell;
          cell = cell->GetNextSibling()) {
-      nsIFrame* contFrame;
-  
-      cell->GetNextInFlow(&contFrame);
+      nsIFrame* contFrame = cell->GetNextInFlow();
       if (contFrame) {
         aStatus =  NS_FRAME_NOT_COMPLETE;
         break;
diff --git a/mozilla/layout/tables/BasicTableLayoutStrategy.cpp b/mozilla/layout/tables/BasicTableLayoutStrategy.cpp
index 0d58e2018e8..8f630ddccaa 100644
--- a/mozilla/layout/tables/BasicTableLayoutStrategy.cpp
+++ b/mozilla/layout/tables/BasicTableLayoutStrategy.cpp
@@ -170,11 +170,8 @@ PRBool BasicTableLayoutStrategy::Initialize(const nsHTMLReflowState& aReflowStat
 
 void BasicTableLayoutStrategy::ContinuingFrameCheck()
 {
-#ifdef NS_DEBUG
-  nsIFrame* tablePIF = nsnull;
-  mTableFrame->GetPrevInFlow(&tablePIF);
-  NS_ASSERTION(!tablePIF, "never ever call me on a continuing frame!");
-#endif
+  NS_ASSERTION(!mTableFrame->GetPrevInFlow(),
+               "never ever call me on a continuing frame!");
 }
 
 PRBool BCW_Wrapup(const nsHTMLReflowState&  aReflowState,
diff --git a/mozilla/layout/tables/nsTableFrame.cpp b/mozilla/layout/tables/nsTableFrame.cpp
index db4af5be795..d595ed3bb28 100644
--- a/mozilla/layout/tables/nsTableFrame.cpp
+++ b/mozilla/layout/tables/nsTableFrame.cpp
@@ -1723,8 +1723,7 @@ void
 nsTableFrame::CheckRequestSpecialHeightReflow(const nsHTMLReflowState& aReflowState)
 {
   if (!aReflowState.frame) ABORT0();
-  nsIFrame* prevInFlow;
-  aReflowState.frame->GetPrevInFlow(&prevInFlow);
+  nsIFrame* prevInFlow = aReflowState.frame->GetPrevInFlow();
 
   if (!prevInFlow                                             &&   // 1st in flow                                            && // 1st in flow
       ((NS_UNCONSTRAINEDSIZE == aReflowState.mComputedHeight) ||   // no computed height
@@ -3104,8 +3103,7 @@ nsTableFrame::OrderRowGroups(nsVoidArray&           aChildren,
     // Get the next sibling but skip it if it's also the next-in-flow, since
     // a next-in-flow will not be part of the current table.
     while (kidFrame) {
-      nsIFrame* nif;
-      kidFrame->GetNextInFlow(&nif);
+      nsIFrame* nif = kidFrame->GetNextInFlow();
       kidFrame = kidFrame->GetNextSibling();
       if (kidFrame != nif) 
         break;
@@ -3219,8 +3217,7 @@ nsTableFrame::ReflowChildren(nsPresContext*     aPresContext,
         
         // record the next in flow in case it gets destroyed and the row group array
         // needs to be recomputed.
-        nsIFrame* kidNextInFlow;
-        kidFrame->GetNextInFlow(&kidNextInFlow);
+        nsIFrame* kidNextInFlow = kidFrame->GetNextInFlow();
   
         rv = ReflowChild(kidFrame, aPresContext, desiredSize, kidReflowState,
                          aReflowState.x, aReflowState.y, 0, aStatus);
@@ -3243,7 +3240,7 @@ nsTableFrame::ReflowChildren(nsPresContext*     aPresContext,
  
         // Special handling for incomplete children
         if (NS_FRAME_IS_NOT_COMPLETE(aStatus)) {         
-          kidFrame->GetNextInFlow(&kidNextInFlow);
+          kidNextInFlow = kidFrame->GetNextInFlow();
           if (!kidNextInFlow) {
             // The child doesn't have a next-in-flow so create a continuing
             // frame. This hooks the child into the flow
@@ -7487,12 +7484,11 @@ void DumpTableFramesRecur(nsIFrame*       aFrame,
   GetFrameTypeName(fType, fName);
 
   printf("%s%s %p", indent, fName, aFrame);
-  nsIFrame* flowFrame;
-  aFrame->GetPrevInFlow(&flowFrame);
+  nsIFrame* flowFrame = aFrame->GetPrevInFlow();
   if (flowFrame) {
     printf(" pif=%p", flowFrame);
   }
-  aFrame->GetNextInFlow(&flowFrame);
+  flowFrame = aFrame->GetNextInFlow();
   if (flowFrame) {
     printf(" nif=%p", flowFrame);
   }
@@ -7516,15 +7512,15 @@ nsTableFrame::DumpTableFrames(nsIFrame* aFrame)
   nsTableFrame* tableFrame = nsnull;
 
   if (nsLayoutAtoms::tableFrame == aFrame->GetType()) { 
-    tableFrame = (nsTableFrame*)aFrame;
+    tableFrame = NS_STATIC_CAST(nsTableFrame*, aFrame);
   }
   else {
     nsTableFrame::GetTableFrame(aFrame, tableFrame);
   }
-  tableFrame = (nsTableFrame*)tableFrame->GetFirstInFlow();
+  tableFrame = NS_STATIC_CAST(nsTableFrame*, tableFrame->GetFirstInFlow());
   while (tableFrame) {
     DumpTableFramesRecur(tableFrame, 0);
-    tableFrame->GetNextInFlow((nsIFrame**)&tableFrame);
+    tableFrame = NS_STATIC_CAST(nsTableFrame*, tableFrame->GetNextInFlow());
   }
 }
 
@@ -7532,4 +7528,3 @@ nsTableFrame::DumpTableFrames(nsIFrame* aFrame)
 
 
 
-
diff --git a/mozilla/layout/tables/nsTableOuterFrame.cpp b/mozilla/layout/tables/nsTableOuterFrame.cpp
index 22b7f908ea4..9d7ca357618 100644
--- a/mozilla/layout/tables/nsTableOuterFrame.cpp
+++ b/mozilla/layout/tables/nsTableOuterFrame.cpp
@@ -2116,9 +2116,7 @@ void nsTableOuterFrame::DeleteChildsNextInFlow(nsPresContext* aPresContext,
   if (!aChild) return;
   NS_PRECONDITION(mFrames.ContainsFrame(aChild), "bad geometric parent");
 
-  nsIFrame* nextInFlow;
-   
-  aChild->GetNextInFlow(&nextInFlow);
+  nsIFrame* nextInFlow = aChild->GetNextInFlow();
   if (!nextInFlow) {
     NS_ASSERTION(PR_FALSE, "null next-in-flow");
     return;
@@ -2132,9 +2130,7 @@ void nsTableOuterFrame::DeleteChildsNextInFlow(nsPresContext* aPresContext,
   }
   // If the next-in-flow has a next-in-flow then delete it too (and
   // delete it first).
-  nsIFrame* nextNextInFlow;
-
-  nextInFlow->GetNextInFlow(&nextNextInFlow);
+  nsIFrame* nextNextInFlow = nextInFlow->GetNextInFlow();
   if (nextNextInFlow) {
     parent->DeleteChildsNextInFlow(aPresContext, nextInFlow);
   }
@@ -2159,10 +2155,7 @@ void nsTableOuterFrame::DeleteChildsNextInFlow(nsPresContext* aPresContext,
   // Delete the next-in-flow frame and adjust it's parent's child count
   nextInFlow->Destroy(aPresContext);
 
-#ifdef NS_DEBUG
-  aChild->GetNextInFlow(&nextInFlow);
-  NS_POSTCONDITION(nsnull == nextInFlow, "non null next-in-flow");
-#endif
+  NS_POSTCONDITION(!aChild->GetNextInFlow(), "non null next-in-flow");
 }
 
 nsIAtom*
diff --git a/mozilla/layout/tables/nsTableRowFrame.cpp b/mozilla/layout/tables/nsTableRowFrame.cpp
index 38fc27e42ff..a7b9ce76282 100644
--- a/mozilla/layout/tables/nsTableRowFrame.cpp
+++ b/mozilla/layout/tables/nsTableRowFrame.cpp
@@ -783,7 +783,7 @@ nscoord CalcHeightFromUnpaginatedHeight(nsPresContext*  aPresContext,
   if (firstInFlow->HasUnpaginatedHeight()) {
     height = firstInFlow->GetUnpaginatedHeight(aPresContext);
     for (nsIFrame* prevInFlow = aRow.GetPrevInFlow(); prevInFlow;
-         prevInFlow->GetPrevInFlow(&prevInFlow)) {
+         prevInFlow = prevInFlow->GetPrevInFlow()) {
       height -= prevInFlow->GetSize().height;
     }
   }
@@ -806,8 +806,7 @@ nsTableRowFrame::ReflowChildren(nsPresContext*          aPresContext,
   GET_PIXELS_TO_TWIPS(aPresContext, p2t);
   PRBool borderCollapse = (((nsTableFrame*)aTableFrame.GetFirstInFlow())->IsBorderCollapse());
 
-  nsIFrame* tablePrevInFlow;
-  aTableFrame.GetPrevInFlow(&tablePrevInFlow);
+  nsIFrame* tablePrevInFlow = aTableFrame.GetPrevInFlow();
   PRBool isPaginated = aPresContext->IsPaginated();
 
   nsresult rv = NS_OK;
@@ -899,8 +898,7 @@ nsTableRowFrame::ReflowChildren(nsPresContext*          aPresContext,
         // the cell wants to be bigger than what was available last time or
         // it is a style change reflow or we are printing, then we must reflow the
         // cell. Otherwise we can skip the reflow.
-        nsIFrame* kidNextInFlow;
-        kidFrame->GetNextInFlow(&kidNextInFlow);
+        nsIFrame* kidNextInFlow = kidFrame->GetNextInFlow();
         nsSize cellDesiredSize = cellFrame->GetDesiredSize();
         if ((availCellWidth != cellFrame->GetPriorAvailWidth())       ||
             (cellDesiredSize.width > cellFrame->GetPriorAvailWidth()) ||
@@ -1348,9 +1346,7 @@ nsTableRowFrame::IR_TargetIsChild(nsPresContext*          aPresContext,
   if (mNextInFlow) {
     for (nsIFrame* cell = mFrames.FirstChild(); cell;
          cell = cell->GetNextSibling()) {
-      nsIFrame* contFrame;
-  
-      cell->GetNextInFlow(&contFrame);
+      nsIFrame* contFrame = cell->GetNextInFlow();
       if (contFrame) {
         aStatus =  NS_FRAME_NOT_COMPLETE;
         break;
diff --git a/mozilla/layout/xul/base/src/nsBoxObject.cpp b/mozilla/layout/xul/base/src/nsBoxObject.cpp
index 82677fc6b8d..3360bb8a919 100644
--- a/mozilla/layout/xul/base/src/nsBoxObject.cpp
+++ b/mozilla/layout/xul/base/src/nsBoxObject.cpp
@@ -201,7 +201,7 @@ nsBoxObject::GetOffsetRect(nsRect& aRect)
         nsIFrame* next = frame;
         do {
           rcFrame.UnionRect(rcFrame, next->GetRect());
-          next->GetNextInFlow(&next);
+          next = next->GetNextInFlow();
         } while (nsnull != next);