Reset ThreadState weak callback stack before GCing.

third_party/WebKit/Source/platform/heap/ThreadState.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 946 matching lines @@
         m_arenas[i]->makeConsistentForMutator();
 }
 
 void ThreadState::preGC()
 {
     ASSERT(!isInGC());
     setGCState(GCRunning);
     makeConsistentForGC();
     flushHeapDoesNotContainCacheIfNeeded();
     clearArenaAges();
+    m_threadLocalWeakCallbackStack->clear();
 }
 
 void ThreadState::postGC(BlinkGC::GCType gcType)
 {
     ASSERT(isInGC());
     for (int i = 0; i < BlinkGC::NumberOfArenas; i++)
         m_arenas[i]->prepareForSweep();
 
     if (gcType == BlinkGC::GCWithSweep) {
         setGCState(EagerSweepScheduled);
@@ skipping 551 matching lines @@
     threadDump->AddScalar("dead_count", "objects", totalDeadCount);
     threadDump->AddScalar("live_size", "bytes", totalLiveSize);
     threadDump->AddScalar("dead_size", "bytes", totalDeadSize);
 
     base::trace_event::MemoryAllocatorDump* heapsDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(heapsDumpName);
     base::trace_event::MemoryAllocatorDump* classesDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(classesDumpName);
     BlinkGCMemoryDumpProvider::instance()->currentProcessMemoryDump()->AddOwnershipEdge(classesDump->guid(), heapsDump->guid());
 }
 
 } // namespace blink