Fix and adjust PageNavigationGC threshold

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 557 matching lines @@
     return judgeGCThreshold(1024 * 1024, 1.5);
 }
 
 bool ThreadState::shouldScheduleV8FollowupGC()
 {
     return judgeGCThreshold(32 * 1024 * 1024, 1.5);
 }
 
 bool ThreadState::shouldSchedulePageNavigationGC(float estimatedRemovalRatio)
 {
-    return judgeGCThreshold(1024 * 1024, 1.5 * (1 - estimatedRemovalRatio));
+    // If estimatedRemovalRatio is low we should let IdleGC handle this.
+    if (estimatedRemovalRatio < 0.01)
+        return false;
+    return judgeGCThreshold(32 * 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 76 matching lines @@
         dataLogF("Scheduled MemoryPressureGC\n");
 #endif
         Heap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::MemoryPressureGC);
         return;
     }
     if (shouldSchedulePageNavigationGC(estimatedRemovalRatio)) {
 #if PRINT_HEAP_STATS
         dataLogF("Scheduled PageNavigationGC\n");
 #endif
         schedulePageNavigationGC();
-        return;
     }
 }
 
 void ThreadState::schedulePageNavigationGC()
 {
     ASSERT(checkThread());
     ASSERT(!isSweepingInProgress());
     setGCState(PageNavigationGCScheduled);
 }
 
@@ skipping 851 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