patch from issue 1063083002 at patchset 20001 (http://crrev.com/1063083002#ps20001)

Source/platform/heap/Heap.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 2639 matching lines @@
     }
     delete current;
 }
 
 void Heap::resetHeapCounters()
 {
     ASSERT(ThreadState::current()->isInGC());
 
     s_allocatedObjectSize = 0;
     s_markedObjectSize = 0;
-
-    // Similarly, reset the amount of externally allocated memory.
-    s_externallyAllocatedBytes = 0;
-    s_externallyAllocatedBytesAlive = 0;
-
-    s_requestedUrgentGC = false;
-}
-
-void Heap::requestUrgentGC()
-{
-    // The urgent-gc flag will be considered the next time an out-of-line
-    // allocation is made. Bump allocations from the current block will
-    // go ahead until it can no longer service an allocation request.
-    //
-    // FIXME: if that delays urgently needed GCs for too long, consider
-    // flushing out per-heap "allocation points" to trigger the GC
-    // right away.
-    releaseStore(&s_requestedUrgentGC, 1);
 }
 
 Visitor* Heap::s_markingVisitor;
 CallbackStack* Heap::s_markingStack;
 CallbackStack* Heap::s_postMarkingCallbackStack;
 CallbackStack* Heap::s_weakCallbackStack;
 CallbackStack* Heap::s_ephemeronStack;
 HeapDoesNotContainCache* Heap::s_heapDoesNotContainCache;
 bool Heap::s_shutdownCalled = false;
 bool Heap::s_lastGCWasConservative = false;
 FreePagePool* Heap::s_freePagePool;
 OrphanedPagePool* Heap::s_orphanedPagePool;
 Heap::RegionTree* Heap::s_regionTree = nullptr;
 size_t Heap::s_allocatedObjectSize = 0;
 size_t Heap::s_allocatedSpace = 0;
 size_t Heap::s_markedObjectSize = 0;
 // We don't want to use 0 KB for the initial value because it may end up
 // triggering the first GC of some thread too prematurely.
 size_t Heap::s_estimatedLiveObjectSize = 512 * 1024;
-
-size_t Heap::s_externallyAllocatedBytes = 0;
-size_t Heap::s_externallyAllocatedBytesAlive = 0;
-unsigned Heap::s_requestedUrgentGC = false;
+size_t Heap::s_externalObjectSizeAtLastGC = 0;
 double Heap::s_estimatedMarkingTimePerByte = 0.0;
 
 } // namespace blink