Collect phantom callback data only once during gc. For scavenges, just consider the young handles r…

src/global-handles.h

 // Copyright 2011 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_GLOBAL_HANDLES_H_
 #define V8_GLOBAL_HANDLES_H_
 
 #include "include/v8.h"
 #include "include/v8-profiler.h"
 
@@ skipping 147 matching lines @@
   // These handles are also included in NumberOfWeakHandles().
   int NumberOfGlobalObjectWeakHandles();
 
   // Returns the current number of handles to global objects.
   int global_handles_count() const {
     return number_of_global_handles_;
   }
 
   // Collect up data for the weak handle callbacks after GC has completed, but
   // before memory is reclaimed.
-  void CollectPhantomCallbackData();
+  void CollectAllPhantomCallbackData();
+
+  // Collect up data for the weak handle callbacks referenced by young
+  // generation after GC has completed, but before memory is reclaimed.
+  void CollectYoungPhantomCallbackData();
 
   // Clear the weakness of a global handle.
   static void* ClearWeakness(Object** location);
 
   // Clear the weakness of a global handle.
   static void MarkIndependent(Object** location);
 
   // Mark the reference to this object externaly unreachable.
   static void MarkPartiallyDependent(Object** location);
 
@@ skipping 247 matching lines @@
   List<int> new_space_indices_;
   int singleton_handles_[NUMBER_OF_SINGLETON_HANDLES];
 
   DISALLOW_COPY_AND_ASSIGN(EternalHandles);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBAL_HANDLES_H_