Do not do post GC processing for scavenges....

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 3073)
+++ src/heap.cc	(working copy)
@@ -478,8 +478,14 @@
 
   Counters::objs_since_last_young.Set(0);
 
-  PostGarbageCollectionProcessing();
+  if (collector == MARK_COMPACTOR) {
+    DisableAssertNoAllocation allow_allocation;
+    GlobalHandles::PostGarbageCollectionProcessing();
+  }
 
+  // Update relocatables.
+  Relocatable::PostGarbageCollectionProcessing();
+
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
     amount_of_external_allocated_memory_at_last_global_gc_ =
@@ -494,17 +500,6 @@
 }
 
 
-void Heap::PostGarbageCollectionProcessing() {
-  // Process weak handles post gc.
-  {
-    DisableAssertNoAllocation allow_allocation;
-    GlobalHandles::PostGarbageCollectionProcessing();
-  }
-  // Update relocatables.
-  Relocatable::PostGarbageCollectionProcessing();
-}
-
-
 void Heap::MarkCompact(GCTracer* tracer) {
   gc_state_ = MARK_COMPACT;
   mc_count_++;