Add an interface for an embedder to provide information about native

test/cctest/test-mark-compact.cc

 // 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 321 matching lines @@
 
   Handle<Object> root = GlobalHandles::Create(*g1s1);  // make a root.
 
   // Connect group 1 and 2, make a cycle.
   Handle<FixedArray>::cast(g1s2)->set(0, *g2s2);
   Handle<FixedArray>::cast(g2s1)->set(0, *g1s1);
 
   {
     Object** g1_objects[] = { g1s1.location(), g1s2.location() };
     Object** g2_objects[] = { g2s1.location(), g2s2.location() };
-    GlobalHandles::AddGroup(g1_objects, 2);
-    GlobalHandles::AddGroup(g2_objects, 2);
+    GlobalHandles::AddGroup(g1_objects, 2, NULL);
+    GlobalHandles::AddGroup(g2_objects, 2, NULL);
   }
   // Do a full GC
   Heap::CollectGarbage(OLD_POINTER_SPACE);
 
   // All object should be alive.
   CHECK_EQ(0, NumberOfWeakCalls);
 
   // Weaken the root.
   GlobalHandles::MakeWeak(root.location(),
                           reinterpret_cast<void*>(1234),
                           &WeakPointerCallback);
 
   // Groups are deleted, rebuild groups.
   {
     Object** g1_objects[] = { g1s1.location(), g1s2.location() };
     Object** g2_objects[] = { g2s1.location(), g2s2.location() };
-    GlobalHandles::AddGroup(g1_objects, 2);
-    GlobalHandles::AddGroup(g2_objects, 2);
+    GlobalHandles::AddGroup(g1_objects, 2, NULL);
+    GlobalHandles::AddGroup(g2_objects, 2, NULL);
   }
 
   Heap::CollectGarbage(OLD_POINTER_SPACE);
 
   // All objects should be gone. 5 global handles in total.
   CHECK_EQ(5, NumberOfWeakCalls);
 }