Make sure idle notifications perform a round of incremental GCs after context disposal.

src/heap.h

 // Copyright 2012 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 1972 matching lines @@
 
   void FinishIdleRound() {
     mark_sweeps_since_idle_round_started_ = kMaxMarkSweepsInIdleRound;
     scavenges_since_last_idle_round_ = 0;
   }
 
   bool EnoughGarbageSinceLastIdleRound() {
     return (scavenges_since_last_idle_round_ >= kIdleScavengeThreshold);
   }
 
-  bool WorthStartingGCWhenIdle() {
-    if (contexts_disposed_ > 0) {
-      return true;
-    }
-    return incremental_marking()->WorthActivating();
-  }
-
   // Estimates how many milliseconds a Mark-Sweep would take to complete.
   // In idle notification handler we assume that this function will return:
   // - 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;
@@ skipping 712 matching lines @@
   AssertNoAllocation no_alloc;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG || LIVE_OBJECT_LIST
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_