Reinstate memory pressure Oilpan GC check post V8 major GCs.

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 686 matching lines @@
     bool shouldForceConservativeGC();
     // V8 minor or major GC is likely to drop a lot of references to objects
     // on Oilpan's heap. We give a chance to schedule a GC.
     bool shouldScheduleV8FollowupGC();
     // Page navigation is likely to drop a lot of references to objects
     // on Oilpan's heap. We give a chance to schedule a GC.
     // estimatedRemovalRatio is the estimated ratio of objects that will be no
     // longer necessary due to the navigation.
     bool shouldSchedulePageNavigationGC(float estimatedRemovalRatio);
 
-    // Internal helper for GC policy handling code. Returns true if
-    // an urgent conservative GC is now needed due to memory pressure.
+    // Internal helpers to handle memory pressure conditions.
+
+    // Returns true if memory use is in a near-OOM state
+    // (aka being under "memory pressure".)
     bool shouldForceMemoryPressureGC();
+
+    // Returns true if shouldForceMemoryPressureGC() held and a
+    // conservative GC was performed to handle the emergency.
+    bool forceMemoryPressureGCIfNeeded();
+
     size_t estimatedLiveSize(size_t currentSize, size_t sizeAtLastGC);
     size_t totalMemorySize();
     double heapGrowingRate();
     double partitionAllocGrowingRate();
     bool judgeGCThreshold(size_t allocatedObjectSizeThreshold, double heapGrowingRateThreshold);
 
     void runScheduledGC(StackState);
 
     void eagerSweep();
 
@@ skipping 111 matching lines @@
 };
 
 template<> class ThreadStateFor<AnyThread> {
 public:
     static ThreadState* state() { return ThreadState::current(); }
 };
 
 } // namespace blink
 
 #endif // ThreadState_h