Start incremental marking on idle notification.

src/incremental-marking.h

 // Copyright 2011 the V8 project authors. 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
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 45 matching lines @@
   }
 
   bool should_hurry() { return should_hurry_; }
 
   inline bool IsStopped() { return state() == STOPPED; }
 
   inline bool IsMarking() { return state() >= MARKING; }
 
   inline bool IsMarkingIncomplete() { return state() == MARKING; }
 
+  inline bool IsComplete() { return state() == COMPLETE; }
+
   bool WorthActivating();
 
   void Start();
 
   void Stop();
 
   void PrepareForScavenge();
 
   void UpdateMarkingDequeAfterScavenge();
 
@@ skipping 14 matching lines @@
   // Start off by marking this many times more memory than has been allocated.
   static const intptr_t kInitialAllocationMarkingFactor = 1;
   // But if we are promoting a lot of data we need to mark faster to keep up
   // with the data that is entering the old space through promotion.
   static const intptr_t kFastMarking = 3;
   // After this many steps we increase the marking/allocating factor.
   static const intptr_t kAllocationMarkingFactorSpeedupInterval = 1024;
   // This is how much we increase the marking/allocating factor by.
   static const intptr_t kAllocationMarkingFactorSpeedup = 2;
   static const intptr_t kMaxAllocationMarkingFactor = 1000000000;
+  // This is given to Step() function when it is called without any allocation.
+  static const intptr_t kStepFakeAllocatedBytes = kAllocatedThreshold * 3;
+
 
   void OldSpaceStep(intptr_t allocated) {
     Step(allocated * kFastMarking / kInitialAllocationMarkingFactor);
   }
   void Step(intptr_t allocated);
 
   inline void RestartIfNotMarking() {
     if (state_ == COMPLETE) {
       state_ = MARKING;
       if (FLAG_trace_incremental_marking) {
@@ skipping 135 matching lines @@
   bool should_hurry_;
   int allocation_marking_factor_;
   intptr_t allocated_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_INCREMENTAL_MARKING_H_