Bug 399852. Experimental relanding to collect data from centos5.

layout/base/nsCSSFrameConstructor.h

@@ -52,6 +52,7 @@
 #include "nsHashKeys.h"
 #include "nsThreadUtils.h"
 #include "nsPageContentFrame.h"
+#include "nsIViewManager.h"
 
 class nsIDocument;
 struct nsFrameItems;
@@ -73,6 +74,19 @@ struct nsFindFrameHint
   nsFindFrameHint() : mPrimaryFrameForPrevSibling(nsnull) { }
 };
 
+// Class which makes an nsIPresShell's ViewManager supress
+// focus/blur events. This prevents the frame tree from being changed
+// by focus handlers etc while *we* are trying to change it.
+// Fix for bug 399852.
+class nsFocusEventSuppressor
+{
+public:
+  void Suppress(nsIPresShell *aPresShell);
+  void Unsuppress();
+private:
+  nsCOMPtr<nsIViewManager> mViewManager;
+};
+
 typedef void (PR_CALLBACK nsLazyFrameConstructionCallback)
              (nsIContent* aContent, nsIFrame* aFrame, void* aArg);
 
@@ -148,7 +162,7 @@ public:
                             PRInt32     aModType,
                             PRUint32    aStateMask);
 
-  void BeginUpdate() { ++mUpdateCount; }
+  void BeginUpdate();
   void EndUpdate();
   void RecalcQuotesAndCounters();
 
@@ -162,6 +176,9 @@ public:
   nsresult ProcessRestyledFrames(nsStyleChangeList& aRestyleArray);
 
 private:
+
+  nsFocusEventSuppressor mFocusSuppressor;
+
   // Note: It's the caller's responsibility to make sure to wrap a
   // ProcessOneRestyle call in a view update batch.
   // This function does not call ProcessAttachedQueue() on the binding manager.