diff --git a/mozilla/content/shared/public/nsLayoutAtomList.h b/mozilla/content/shared/public/nsLayoutAtomList.h
index da644548bbf..b62ad645fbe 100644
--- a/mozilla/content/shared/public/nsLayoutAtomList.h
+++ b/mozilla/content/shared/public/nsLayoutAtomList.h
@@ -103,6 +103,7 @@ LAYOUT_ATOM(viewportFrame, "ViewportFrame")
 LAYOUT_ATOM(cellMap, "TableCellMap")
 LAYOUT_ATOM(imageMap, "ImageMap")
 LAYOUT_ATOM(lineBox, "LineBox")
+LAYOUT_ATOM(lineBoxFloaters, "LineBoxFloaters")
 LAYOUT_ATOM(spaceManager, "SpaceManager")
 LAYOUT_ATOM(tableStrategy, "TableLayoutStrategy")
 LAYOUT_ATOM(textRun, "TextRun")
diff --git a/mozilla/layout/base/nsLayoutAtomList.h b/mozilla/layout/base/nsLayoutAtomList.h
index da644548bbf..b62ad645fbe 100644
--- a/mozilla/layout/base/nsLayoutAtomList.h
+++ b/mozilla/layout/base/nsLayoutAtomList.h
@@ -103,6 +103,7 @@ LAYOUT_ATOM(viewportFrame, "ViewportFrame")
 LAYOUT_ATOM(cellMap, "TableCellMap")
 LAYOUT_ATOM(imageMap, "ImageMap")
 LAYOUT_ATOM(lineBox, "LineBox")
+LAYOUT_ATOM(lineBoxFloaters, "LineBoxFloaters")
 LAYOUT_ATOM(spaceManager, "SpaceManager")
 LAYOUT_ATOM(tableStrategy, "TableLayoutStrategy")
 LAYOUT_ATOM(textRun, "TextRun")
diff --git a/mozilla/layout/base/public/nsLayoutAtomList.h b/mozilla/layout/base/public/nsLayoutAtomList.h
index da644548bbf..b62ad645fbe 100644
--- a/mozilla/layout/base/public/nsLayoutAtomList.h
+++ b/mozilla/layout/base/public/nsLayoutAtomList.h
@@ -103,6 +103,7 @@ LAYOUT_ATOM(viewportFrame, "ViewportFrame")
 LAYOUT_ATOM(cellMap, "TableCellMap")
 LAYOUT_ATOM(imageMap, "ImageMap")
 LAYOUT_ATOM(lineBox, "LineBox")
+LAYOUT_ATOM(lineBoxFloaters, "LineBoxFloaters")
 LAYOUT_ATOM(spaceManager, "SpaceManager")
 LAYOUT_ATOM(tableStrategy, "TableLayoutStrategy")
 LAYOUT_ATOM(textRun, "TextRun")
diff --git a/mozilla/layout/base/src/nsSpaceManager.cpp b/mozilla/layout/base/src/nsSpaceManager.cpp
index 522b7ac1932..19a558f5851 100644
--- a/mozilla/layout/base/src/nsSpaceManager.cpp
+++ b/mozilla/layout/base/src/nsSpaceManager.cpp
@@ -1200,6 +1200,7 @@ nsSpaceManager::BandRect::Length() const
 void
 nsSpaceManager::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
 {
+  NS_PRECONDITION(aResult, "null OUT parameter pointer");
   *aResult = sizeof(*this);
 
   // Add in the size of the band data. Don't count the header which has
diff --git a/mozilla/layout/generic/nsBlockFrame.cpp b/mozilla/layout/generic/nsBlockFrame.cpp
index dcd40ca9bd1..47bbc7daaf6 100644
--- a/mozilla/layout/generic/nsBlockFrame.cpp
+++ b/mozilla/layout/generic/nsBlockFrame.cpp
@@ -5605,12 +5605,16 @@ nsBlockFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
   // Add in size of each line object
   nsLineBox* line = mLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
   line = mOverflowLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
 
diff --git a/mozilla/layout/generic/nsBlockReflowState.cpp b/mozilla/layout/generic/nsBlockReflowState.cpp
index dcd40ca9bd1..47bbc7daaf6 100644
--- a/mozilla/layout/generic/nsBlockReflowState.cpp
+++ b/mozilla/layout/generic/nsBlockReflowState.cpp
@@ -5605,12 +5605,16 @@ nsBlockFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
   // Add in size of each line object
   nsLineBox* line = mLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
   line = mOverflowLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
 
diff --git a/mozilla/layout/generic/nsBlockReflowState.h b/mozilla/layout/generic/nsBlockReflowState.h
index dcd40ca9bd1..47bbc7daaf6 100644
--- a/mozilla/layout/generic/nsBlockReflowState.h
+++ b/mozilla/layout/generic/nsBlockReflowState.h
@@ -5605,12 +5605,16 @@ nsBlockFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
   // Add in size of each line object
   nsLineBox* line = mLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
   line = mOverflowLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
 
diff --git a/mozilla/layout/generic/nsLineBox.cpp b/mozilla/layout/generic/nsLineBox.cpp
index cf69a6f63c0..4fa8a8b2b69 100644
--- a/mozilla/layout/generic/nsLineBox.cpp
+++ b/mozilla/layout/generic/nsLineBox.cpp
@@ -22,6 +22,11 @@
 #include "nsLineLayout.h"
 #include "prprf.h"
 
+#ifdef DEBUG
+#include "nsISizeOfHandler.h"
+#include "nsLayoutAtoms.h"
+#endif
+
 nsLineBox::nsLineBox(nsIFrame* aFrame, PRInt32 aCount, PRUint16 flags)
 {
   mFirstChild = aFrame;
@@ -206,6 +211,25 @@ nsLineBox::CheckIsBlock() const
 }
 #endif
 
+#ifdef DEBUG
+void
+nsLineBox::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
+{
+  NS_PRECONDITION(aResult, "null OUT parameter pointer");
+  *aResult = sizeof(*this);
+
+  // Add in the size needed for floaters associated with this line
+  if (mFloaters.NotEmpty()) {
+    PRUint32  floatersSize;
+
+    mFloaters.SizeOf(aHandler, &floatersSize);
+    // Base size of embedded object was included in sizeof(*this) above
+    floatersSize -= sizeof(mFloaters);
+    aHandler->AddSize(nsLayoutAtoms::lineBoxFloaters, floatersSize);
+  }
+}
+#endif
+
 //----------------------------------------------------------------------
 
 static NS_DEFINE_IID(kILineIteratorIID, NS_ILINE_ITERATOR_IID);
@@ -532,6 +556,20 @@ nsFloaterCacheList::Remove(nsFloaterCache* aElement)
   }
 }
 
+#ifdef DEBUG
+void
+nsFloaterCacheList::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
+{
+  NS_PRECONDITION(aResult, "null OUT parameter pointer");
+  *aResult = sizeof(*this);
+
+  // Add in the space for each floater
+  for (nsFloaterCache* cache = Head(); cache; cache = cache->Next()) {
+    *aResult += sizeof(*cache);
+  }
+}
+#endif
+
 //----------------------------------------------------------------------
 
 void
diff --git a/mozilla/layout/generic/nsLineBox.h b/mozilla/layout/generic/nsLineBox.h
index 7675c2fcf3a..2e753c4c9b7 100644
--- a/mozilla/layout/generic/nsLineBox.h
+++ b/mozilla/layout/generic/nsLineBox.h
@@ -22,6 +22,7 @@
 #include "nsVoidArray.h"
 #include "nsPlaceholderFrame.h"
 #include "nsILineIterator.h"
+#include "nsISizeOfHandler.h"
 
 // bits in nsLineBox.mState
 #define LINE_IS_DIRTY               0x1
@@ -105,6 +106,10 @@ public:
 
   void Append(nsFloaterCacheFreeList& aList);
 
+#ifdef DEBUG
+  void SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const;
+#endif
+
 protected:
   nsFloaterCache* mHead;
 
@@ -257,6 +262,10 @@ public:
   PRBool CheckIsBlock() const;
 #endif
 
+#ifdef DEBUG
+  void SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const;
+#endif
+
   nsIFrame* mFirstChild;
   PRUint16 mChildCount;
   PRUint8 mState;
diff --git a/mozilla/layout/generic/nsSpaceManager.cpp b/mozilla/layout/generic/nsSpaceManager.cpp
index 522b7ac1932..19a558f5851 100644
--- a/mozilla/layout/generic/nsSpaceManager.cpp
+++ b/mozilla/layout/generic/nsSpaceManager.cpp
@@ -1200,6 +1200,7 @@ nsSpaceManager::BandRect::Length() const
 void
 nsSpaceManager::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
 {
+  NS_PRECONDITION(aResult, "null OUT parameter pointer");
   *aResult = sizeof(*this);
 
   // Add in the size of the band data. Don't count the header which has
diff --git a/mozilla/layout/html/base/src/nsBlockFrame.cpp b/mozilla/layout/html/base/src/nsBlockFrame.cpp
index dcd40ca9bd1..47bbc7daaf6 100644
--- a/mozilla/layout/html/base/src/nsBlockFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBlockFrame.cpp
@@ -5605,12 +5605,16 @@ nsBlockFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
   // Add in size of each line object
   nsLineBox* line = mLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
   line = mOverflowLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
 
diff --git a/mozilla/layout/html/base/src/nsBlockReflowState.cpp b/mozilla/layout/html/base/src/nsBlockReflowState.cpp
index dcd40ca9bd1..47bbc7daaf6 100644
--- a/mozilla/layout/html/base/src/nsBlockReflowState.cpp
+++ b/mozilla/layout/html/base/src/nsBlockReflowState.cpp
@@ -5605,12 +5605,16 @@ nsBlockFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
   // Add in size of each line object
   nsLineBox* line = mLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
   line = mOverflowLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
 
diff --git a/mozilla/layout/html/base/src/nsBlockReflowState.h b/mozilla/layout/html/base/src/nsBlockReflowState.h
index dcd40ca9bd1..47bbc7daaf6 100644
--- a/mozilla/layout/html/base/src/nsBlockReflowState.h
+++ b/mozilla/layout/html/base/src/nsBlockReflowState.h
@@ -5605,12 +5605,16 @@ nsBlockFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
   // Add in size of each line object
   nsLineBox* line = mLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
   line = mOverflowLines;
   while (line) {
-    aHandler->AddSize(nsLayoutAtoms::lineBox, sizeof(nsLineBox));
+    PRUint32  lineBoxSize;
+    line->SizeOf(aHandler, &lineBoxSize);
+    aHandler->AddSize(nsLayoutAtoms::lineBox, lineBoxSize);
     line = line->mNext;
   }
 
diff --git a/mozilla/layout/html/base/src/nsLineBox.cpp b/mozilla/layout/html/base/src/nsLineBox.cpp
index cf69a6f63c0..4fa8a8b2b69 100644
--- a/mozilla/layout/html/base/src/nsLineBox.cpp
+++ b/mozilla/layout/html/base/src/nsLineBox.cpp
@@ -22,6 +22,11 @@
 #include "nsLineLayout.h"
 #include "prprf.h"
 
+#ifdef DEBUG
+#include "nsISizeOfHandler.h"
+#include "nsLayoutAtoms.h"
+#endif
+
 nsLineBox::nsLineBox(nsIFrame* aFrame, PRInt32 aCount, PRUint16 flags)
 {
   mFirstChild = aFrame;
@@ -206,6 +211,25 @@ nsLineBox::CheckIsBlock() const
 }
 #endif
 
+#ifdef DEBUG
+void
+nsLineBox::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
+{
+  NS_PRECONDITION(aResult, "null OUT parameter pointer");
+  *aResult = sizeof(*this);
+
+  // Add in the size needed for floaters associated with this line
+  if (mFloaters.NotEmpty()) {
+    PRUint32  floatersSize;
+
+    mFloaters.SizeOf(aHandler, &floatersSize);
+    // Base size of embedded object was included in sizeof(*this) above
+    floatersSize -= sizeof(mFloaters);
+    aHandler->AddSize(nsLayoutAtoms::lineBoxFloaters, floatersSize);
+  }
+}
+#endif
+
 //----------------------------------------------------------------------
 
 static NS_DEFINE_IID(kILineIteratorIID, NS_ILINE_ITERATOR_IID);
@@ -532,6 +556,20 @@ nsFloaterCacheList::Remove(nsFloaterCache* aElement)
   }
 }
 
+#ifdef DEBUG
+void
+nsFloaterCacheList::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
+{
+  NS_PRECONDITION(aResult, "null OUT parameter pointer");
+  *aResult = sizeof(*this);
+
+  // Add in the space for each floater
+  for (nsFloaterCache* cache = Head(); cache; cache = cache->Next()) {
+    *aResult += sizeof(*cache);
+  }
+}
+#endif
+
 //----------------------------------------------------------------------
 
 void
diff --git a/mozilla/layout/html/base/src/nsLineBox.h b/mozilla/layout/html/base/src/nsLineBox.h
index 7675c2fcf3a..2e753c4c9b7 100644
--- a/mozilla/layout/html/base/src/nsLineBox.h
+++ b/mozilla/layout/html/base/src/nsLineBox.h
@@ -22,6 +22,7 @@
 #include "nsVoidArray.h"
 #include "nsPlaceholderFrame.h"
 #include "nsILineIterator.h"
+#include "nsISizeOfHandler.h"
 
 // bits in nsLineBox.mState
 #define LINE_IS_DIRTY               0x1
@@ -105,6 +106,10 @@ public:
 
   void Append(nsFloaterCacheFreeList& aList);
 
+#ifdef DEBUG
+  void SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const;
+#endif
+
 protected:
   nsFloaterCache* mHead;
 
@@ -257,6 +262,10 @@ public:
   PRBool CheckIsBlock() const;
 #endif
 
+#ifdef DEBUG
+  void SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const;
+#endif
+
   nsIFrame* mFirstChild;
   PRUint16 mChildCount;
   PRUint8 mState;
diff --git a/mozilla/layout/html/table/src/nsCellMap.cpp b/mozilla/layout/html/table/src/nsCellMap.cpp
index d2e65e1dafd..b138cbb89a7 100644
--- a/mozilla/layout/html/table/src/nsCellMap.cpp
+++ b/mozilla/layout/html/table/src/nsCellMap.cpp
@@ -704,6 +704,7 @@ PRBool nsCellMap::ColHasSpanningCells(PRInt32 aColIndex) const
 #ifdef DEBUG
 void nsCellMap::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
 {
+  NS_PRECONDITION(aResult, "null OUT parameter pointer");
   PRUint32 sum = sizeof(*this);
 
   // Add in the size of the void arrays. Because we have emnbedded objects
diff --git a/mozilla/layout/tables/nsCellMap.cpp b/mozilla/layout/tables/nsCellMap.cpp
index d2e65e1dafd..b138cbb89a7 100644
--- a/mozilla/layout/tables/nsCellMap.cpp
+++ b/mozilla/layout/tables/nsCellMap.cpp
@@ -704,6 +704,7 @@ PRBool nsCellMap::ColHasSpanningCells(PRInt32 aColIndex) const
 #ifdef DEBUG
 void nsCellMap::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
 {
+  NS_PRECONDITION(aResult, "null OUT parameter pointer");
   PRUint32 sum = sizeof(*this);
 
   // Add in the size of the void arrays. Because we have emnbedded objects