Object.observe: include oldValue in change records,

src/objects-inl.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 5065 matching lines @@
     return JSProxy::cast(this)->HasPropertyWithHandler(name);
   }
   return GetLocalPropertyAttribute(name) != ABSENT;
 }
 
 
 PropertyAttributes JSReceiver::GetPropertyAttribute(String* key) {
   return GetPropertyAttributeWithReceiver(this, key);
 }
 
+
 // TODO(504): this may be useful in other places too where JSGlobalProxy
 // is used.
 Object* JSObject::BypassGlobalProxy() {
   if (IsJSGlobalProxy()) {
     Object* proto = GetPrototype();
     if (proto->IsNull()) return GetHeap()->undefined_value();
     ASSERT(proto->IsJSGlobalObject());
     return proto;
   }
   return this;
@@ skipping 463 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_