Removed IdleGlobalGC and just perform IdleNotification when incremental marking is on.

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_H_
 #define V8_HEAP_H_
 
 #include <cmath>
 
 #include "src/allocation.h"
@@ skipping 2060 matching lines @@
   // - a number less than 10 for small heaps, which are less than 8Mb.
   // - a number greater than 10 for large heaps, which are greater than 32Mb.
   int TimeMarkSweepWouldTakeInMs() {
     // Rough estimate of how many megabytes of heap can be processed in 1 ms.
     static const int kMbPerMs = 2;
 
     int heap_size_mb = static_cast<int>(SizeOfObjects() / MB);
     return heap_size_mb / kMbPerMs;
   }
 
-  // Returns true if no more GC work is left.
-  bool IdleGlobalGC();
-
   void AdvanceIdleIncrementalMarking(intptr_t step_size);
 
   void ClearObjectStats(bool clear_last_time_stats = false);
 
   void set_weak_object_to_code_table(Object* value) {
     ASSERT(!InNewSpace(value));
     weak_object_to_code_table_ = value;
   }
 
   Object** weak_object_to_code_table_address() {
@@ skipping 563 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_