diff --git a/mozilla/layout/base/nsIPresShell.h b/mozilla/layout/base/nsIPresShell.h
index 0e61a289bbc..b093e5e702e 100644
--- a/mozilla/layout/base/nsIPresShell.h
+++ b/mozilla/layout/base/nsIPresShell.h
@@ -97,10 +97,10 @@ class nsWeakFrame;
 
 typedef short SelectionType;
 
-// b6cf677a-aa50-47c2-b381-5a82e7e792da
+// 56719ada-52e9-4d81-b23d-acba10c5c1e2
 #define NS_IPRESSHELL_IID     \
-{ 0xb6cf677a, 0xaa50, 0x47c2, \
-  { 0xb3, 0x81, 0x5a, 0x82, 0xe7, 0xe7, 0x92, 0xda } }
+{ 0x56719ada, 0x52e9, 0x4d81, \
+  { 0xb2, 0x3d, 0xac, 0xba, 0x10, 0xc5, 0xc1, 0xe2 } }
 
 // Constants uses for ScrollFrameIntoView() function
 #define NS_PRESSHELL_SCROLL_TOP      0
@@ -376,11 +376,6 @@ public:
    */
   NS_IMETHOD FlushPendingNotifications(mozFlushType aType) = 0;
 
-  /**
-   * Post a request to handle a DOM event after Reflow has finished.
-   */
-  NS_IMETHOD PostDOMEvent(nsIContent* aContent, nsEvent* aEvent)=0;
-
   /**
    * Post a request to set and attribute after reflow has finished.
    */
diff --git a/mozilla/layout/base/nsPresShell.cpp b/mozilla/layout/base/nsPresShell.cpp
index 841ad8d2418..0da230e0944 100644
--- a/mozilla/layout/base/nsPresShell.cpp
+++ b/mozilla/layout/base/nsPresShell.cpp
@@ -844,11 +844,6 @@ public:
    */
   NS_IMETHOD RecreateFramesFor(nsIContent* aContent);
 
-  /**
-   * Post a request to handle a DOM event after Reflow has finished.
-   */
-  NS_IMETHOD PostDOMEvent(nsIContent* aContent, nsEvent* aEvent);
-
   /**
    * Post a request to set and attribute after reflow has finished.
    */
@@ -1156,10 +1151,7 @@ protected:
   
   nsRevocableEventPtr<ReflowEvent> mReflowEvent;
 
-  // used for list of posted events and attribute changes. To be done
-  // after reflow.
-  nsDOMEventRequest* mFirstDOMEventRequest;
-  nsDOMEventRequest* mLastDOMEventRequest;
+  // used for list of posted attribute changes. To be done after reflow.
   nsAttributeChangeRequest* mFirstAttributeRequest;
   nsAttributeChangeRequest* mLastAttributeRequest;
   nsCallbackEventRequest* mFirstCallbackEventRequest;
@@ -1426,9 +1418,7 @@ PresShell::~PresShell()
 
   NS_ASSERTION(mCurrentEventContentStack.Count() == 0,
                "Huh, event content left on the stack in pres shell dtor!");
-  NS_ASSERTION(mFirstDOMEventRequest == nsnull &&
-               mLastDOMEventRequest == nsnull &&
-               mFirstAttributeRequest == nsnull &&
+  NS_ASSERTION(mFirstAttributeRequest == nsnull &&
                mLastAttributeRequest == nsnull &&
                mFirstCallbackEventRequest == nsnull &&
                mLastCallbackEventRequest == nsnull,
@@ -4671,39 +4661,6 @@ PresShell::CancelReflowCallback(nsIReflowCallback* aCallback)
    return NS_OK;
 }
 
-/**
-* Post a request to handle a DOM event after Reflow has finished.
-* The event must have been created with the "new" operator.
-*/
-NS_IMETHODIMP
-PresShell::PostDOMEvent(nsIContent* aContent, nsEvent* aEvent)
-{
- // ok we have a list of events to handle. Queue them up and handle them
- // after we finish reflow.
-
-  void* result = AllocateFrame(sizeof(nsDOMEventRequest));
-  if (NS_UNLIKELY(!result)) {
-    return NS_ERROR_OUT_OF_MEMORY;
-  }
-  nsDOMEventRequest* request = (nsDOMEventRequest*)result;
-
-  request->content = aContent;
-  NS_ADDREF(aContent);
-
-  request->event = aEvent;
-  request->next = nsnull;
-
-  if (mLastDOMEventRequest) {
-    mLastDOMEventRequest = mLastDOMEventRequest->next = request;
-  } else {
-    mFirstDOMEventRequest = request;
-    mLastDOMEventRequest = request;
-  }
- 
-  return NS_OK;
-}
-
-
 /**
  * Post a request to set and attribute after reflow has finished.
  */
@@ -4767,30 +4724,6 @@ PresShell::HandlePostedReflowCallbacks()
      FlushPendingNotifications(Flush_Layout);
 }
 
-void
-PresShell::HandlePostedDOMEvents()
-{
-   while(mFirstDOMEventRequest)
-   {
-      /* pull the node from the event request list. Be prepared for reentrant access to the list
-         from within Dispatch and its callees! */
-      nsDOMEventRequest* node = mFirstDOMEventRequest;
-      nsEventStatus status = nsEventStatus_eIgnore;
-
-      mFirstDOMEventRequest = node->next;
-      if (nsnull == mFirstDOMEventRequest) {
-        mLastDOMEventRequest = nsnull;
-      }
-
-      nsEventDispatcher::Dispatch(node->content, mPresContext, node->event,
-                                  nsnull, &status);
-      NS_RELEASE(node->content);
-      delete node->event;
-      node->nsDOMEventRequest::~nsDOMEventRequest(); // doesn't do anything, but just in case
-      FreeFrame(sizeof(nsDOMEventRequest), node);
-   }
-}
-
 void
 PresShell::HandlePostedAttributeChanges()
 {
@@ -6174,7 +6107,6 @@ PresShell::WillDoReflow()
 void
 PresShell::DidDoReflow()
 {
-  HandlePostedDOMEvents();
   HandlePostedAttributeChanges();
   HandlePostedReflowCallbacks();
   // Null-check mViewManager in case this happens during Destroy.  See
diff --git a/mozilla/layout/generic/nsGfxScrollFrame.cpp b/mozilla/layout/generic/nsGfxScrollFrame.cpp
index 0b7899bddb9..81c00f78528 100644
--- a/mozilla/layout/generic/nsGfxScrollFrame.cpp
+++ b/mozilla/layout/generic/nsGfxScrollFrame.cpp
@@ -1532,6 +1532,24 @@ nsGfxScrollFrameInner::ScrollToRestoredPosition()
   }
 }
 
+class nsAsyncScrollPortEvent : public nsRunnable
+{
+public:
+  // nsAsyncScrollPortEvent owns aEvent.
+  nsAsyncScrollPortEvent(nsIContent* aTarget, nsPresContext* aPresContext,
+                         nsScrollPortEvent* aEvent)
+  : mTarget(aTarget), mPresContext(aPresContext), mEvent(aEvent) {}
+
+  NS_IMETHOD Run() {
+    nsEventDispatcher::Dispatch(mTarget, mPresContext, mEvent);
+    return NS_OK;
+  }
+private:
+  nsCOMPtr<nsIContent>         mTarget;
+  nsRefPtr<nsPresContext>      mPresContext;
+  nsAutoPtr<nsScrollPortEvent> mEvent;
+};
+
 void
 nsGfxScrollFrameInner::PostScrollPortEvent(PRBool aOverflow, nsScrollPortEvent::orientType aType)
 {
@@ -1539,8 +1557,12 @@ nsGfxScrollFrameInner::PostScrollPortEvent(PRBool aOverflow, nsScrollPortEvent::
                                                    NS_SCROLLPORT_OVERFLOW :
                                                    NS_SCROLLPORT_UNDERFLOW,
                                                    nsnull);
+  ENSURE_TRUE(event);
   event->orient = aType;
-  mOuter->GetPresContext()->PresShell()->PostDOMEvent(mOuter->GetContent(), event);
+  nsCOMPtr<nsIRunnable> ev = new nsAsyncScrollPortEvent(mOuter->GetContent(),
+                                                        mOuter->GetPresContext(),
+                                                        event);
+  NS_DispatchToCurrentThread(ev);
 }
 
 void