Fix my memory leak in MessageChannel

webkit/plugins/ppapi/message_channel.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/plugins/ppapi/message_channel.h"
 
 #include <cstdlib>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 324 matching lines @@
                              npvariant_args,
                              sizeof(npvariant_args)/sizeof(*npvariant_args),
                              &result_var);
 }
 
 void MessageChannel::PostMessageToNative(PP_Var message_data) {
   instance_->HandleMessage(message_data);
 }
 
 MessageChannel::~MessageChannel() {
+  WebBindings::releaseObject(np_object_);
   WebBindings::releaseVariantValue(&onmessage_invoker_);
 }
 
 }  // namespace ppapi
 }  // namespace webkit