Bug 1115812 patch 8 - Call BeginProcessingRestyles and EndProcessingRestyles from DoRebuildAllStyleData. r=heycam

This fixes one of the omissions in the rebuild-all codepaths (where it
incorrectly differs from the regular ProcessPendingRestyles codepath).
Note that the explicit FlushOverflowChangedTracker() is no longer needed
because that's part of EndProcessingRestyles.

(This will all get refactored more substantially in the following
patches.)

layout/base/RestyleManager.cpp

@@ -1530,6 +1530,8 @@ RestyleManager::RebuildAllStyleData(nsChangeHint aExtraHint,
 void
 RestyleManager::DoRebuildAllStyleData(RestyleTracker& aRestyleTracker)
 {
+  BeginProcessingRestyles();
+
   mInRebuildAllStyleData = true;
 
   // Tell the style set to get the old rule tree out of the way
@@ -1578,7 +1580,8 @@ RestyleManager::DoRebuildAllStyleData(RestyleTracker& aRestyleTracker)
   // Note: The restyle tracker we pass in here doesn't matter.
   ComputeAndProcessStyleChange(mPresContext->PresShell()->GetRootFrame(),
                                changeHint, aRestyleTracker, restyleHint);
-  FlushOverflowChangedTracker();
+
+  EndProcessingRestyles();
 
   if (mInRebuildAllStyleData) {
     // Tell the style set it's safe to destroy the old rule tree.  We