Revert of Disable page navigation GC

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 546 matching lines @@
     return judgeGCThreshold(1024 * 1024, 1.5);
 }
 
 bool ThreadState::shouldScheduleV8FollowupGC()
 {
     return judgeGCThreshold(32 * 1024 * 1024, 1.5);
 }
 
 bool ThreadState::shouldSchedulePageNavigationGC(float estimatedRemovalRatio)
 {
-    // TODO(keishi): Temporarily disabled to observe impact. crbug.com/588029
-    return false;
+    return judgeGCThreshold(1024 * 1024, 1.5 * (1 - estimatedRemovalRatio));
 }
 
 bool ThreadState::shouldForceConservativeGC()
 {
     // TODO(haraken): 400% is too large. Lower the heap growing factor.
     return judgeGCThreshold(32 * 1024 * 1024, 5.0);
 }
 
 // If we're consuming too much memory, trigger a conservative GC
 // aggressively. This is a safe guard to avoid OOM.
@@ skipping 921 matching lines @@
     threadDump->addScalar("dead_count", "objects", totalDeadCount);
     threadDump->addScalar("live_size", "bytes", totalLiveSize);
     threadDump->addScalar("dead_size", "bytes", totalDeadSize);
 
     WebMemoryAllocatorDump* heapsDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(heapsDumpName);
     WebMemoryAllocatorDump* classesDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(classesDumpName);
     BlinkGCMemoryDumpProvider::instance()->currentProcessMemoryDump()->addOwnershipEdge(classesDump->guid(), heapsDump->guid());
 }
 
 } // namespace blink