Experimental (somewhat): Force GCs when disposing contexts.

src/heap.h

 // Copyright 2006-2008 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 588 matching lines @@
   // Code that should be executed after the garbage collection proper.
   static void PostGarbageCollectionProcessing();
 
   // Performs garbage collection operation.
   // Returns whether required_space bytes are available after the collection.
   static bool CollectGarbage(int required_space, AllocationSpace space);
 
   // Performs a full garbage collection.
   static void CollectAllGarbage();
 
+  // Performs a full garbage collection if a context has been disposed
+  // since the last time the check was performed.
+  static void CollectAllGarbageIfContextDisposed();
+
+  // Notify the heap that a context has been disposed.
+  static void NotifyContextDisposed();
+
   // Utility to invoke the scavenger. This is needed in test code to
   // ensure correct callback for weak global handles.
   static void PerformScavenge();
 
 #ifdef DEBUG
   // Utility used with flag gc-greedy.
   static bool GarbageCollectionGreedyCheck();
 #endif
 
   static void SetGlobalGCPrologueCallback(GCCallback callback) {
@@ skipping 182 matching lines @@
  private:
   static int semispace_size_;
   static int initial_semispace_size_;
   static int young_generation_size_;
   static int old_generation_size_;
 
   static int new_space_growth_limit_;
   static int scavenge_count_;
 
   static int always_allocate_scope_depth_;
+  static bool context_disposed_pending_;
 
   static const int kMaxMapSpaceSize = 8*MB;
 
   static NewSpace new_space_;
   static OldSpace* old_pointer_space_;
   static OldSpace* old_data_space_;
   static OldSpace* code_space_;
   static MapSpace* map_space_;
   static LargeObjectSpace* lo_space_;
   static HeapState gc_state_;
@@ skipping 459 matching lines @@
   int marked_count_;
 
   // The count from the end of the previous full GC.  Will be zero if there
   // was no previous full GC.
   int previous_marked_count_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_