Oilpan: We shouldn't trigger too many conservative GCs when detaching iframes

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

 /*
  * 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 318 matching lines @@
 
     void performIdleGC(double deadlineSeconds);
     void performIdleLazySweep(double deadlineSeconds);
 
     void scheduleIdleGC();
     void scheduleIdleLazySweep();
     void schedulePreciseGC();
     void scheduleV8FollowupGCIfNeeded(V8GCType);
     void schedulePageNavigationGCIfNeeded(float estimatedRemovalRatio);
     void schedulePageNavigationGC();
+    void v8ContextCreated();
+    void v8ContextDisposed();
+
     void scheduleGCIfNeeded();
     void setGCState(GCState);
     GCState gcState() const;
     bool isInGC() const { return gcState() == GCRunning; }
     bool isSweepingInProgress() const
     {
         return gcState() == Sweeping || gcState() == SweepingAndPreciseGCScheduled || gcState() == SweepingAndIdleGCScheduled;
     }
 
     // A GC runs in the following sequence.
@@ skipping 431 matching lines @@
     intptr_t* m_endOfStack;
     void* m_safePointScopeMarker;
     Vector<Address> m_safePointStackCopy;
     bool m_atSafePoint;
     InterruptorVector m_interruptors;
     bool m_sweepForbidden;
     size_t m_noAllocationCount;
     size_t m_gcForbiddenCount;
     int m_persistentAllocated;
     int m_persistentFreed;
+    int m_disposedV8ContextCount;
     BaseHeap* m_heaps[NumberOfHeaps];
 
     int m_vectorBackingHeapIndex;
     size_t m_heapAges[NumberOfHeaps];
     size_t m_currentHeapAges;
 
     bool m_isTerminating;
     GarbageCollectedMixinConstructorMarker* m_gcMixinMarker;
 
     bool m_shouldFlushHeapDoesNotContainCache;
@@ skipping 38 matching lines @@
 };
 
 template<> class ThreadStateFor<AnyThread> {
 public:
     static ThreadState* state() { return ThreadState::current(); }
 };
 
 } // namespace blink
 
 #endif // ThreadState_h