Provide more accurate results about used heap size via GetHeapStatistics.

src/heap.cc

 // Copyright 2010 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 382 matching lines @@
 
 intptr_t Heap::SizeOfObjects() {
   intptr_t total = 0;
   AllSpaces spaces;
   for (Space* space = spaces.next(); space != NULL; space = spaces.next()) {
     total += space->Size();
   }
   return total;
 }
 
+intptr_t Heap::SizeOfObjectsSlow() {
+  intptr_t total = 0;
+  HeapIterator iterator;
+  for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
+    if (!FreeListNode::IsFreeListNode(obj)) {
+      total += obj->Size();
+    }
+  }
+  return total;
+}
+
 void Heap::GarbageCollectionEpilogue() {
 #ifdef DEBUG
   allow_allocation(true);
   ZapFromSpace();
 
   if (FLAG_verify_heap) {
     Verify();
   }
 
   if (FLAG_print_global_handles) GlobalHandles::Print();
@@ skipping 4873 matching lines @@
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 List<Object*> ExternalStringTable::new_space_strings_;
 List<Object*> ExternalStringTable::old_space_strings_;
 
 } }  // namespace v8::internal