Fix another race condition on worker process shutdown that results in use-aft...

chrome/renderer/webworker_proxy.cc

 // Copyright (c) 2009 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 "chrome/renderer/webworker_proxy.h"
 
 #include "chrome/common/child_thread.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/webmessageportchannel_impl.h"
 #include "chrome/common/worker_messages.h"
@@ skipping 79 matching lines @@
 
   Send(new WorkerMsg_PostMessage(
       route_id_, message, message_port_ids, routing_ids));
 }
 
 void WebWorkerProxy::workerObjectDestroyed() {
   Send(new WorkerMsg_WorkerObjectDestroyed(route_id_));
   delete this;
 }
 
+void WebWorkerProxy::clientDestroyed() {
+}
+
 bool WebWorkerProxy::Send(IPC::Message* message) {
   // It's possible that postMessage is called before the worker is created, in
   // which case route_id_ will be none.  Or the worker object can be interacted
   // with before the browser process told us that it started, in which case we
   // also want to queue the message.
   if (route_id_ == MSG_ROUTING_NONE || !queued_messages_.empty()) {
     queued_messages_.push_back(message);
     return true;
   }
 
@@ skipping 54 matching lines @@
   client_->postMessageToWorkerObject(message, channels);
 }
 
 void WebWorkerProxy::OnPostConsoleMessageToWorkerObject(
       const WorkerHostMsg_PostConsoleMessageToWorkerObject_Params& params) {
   client_->postConsoleMessageToWorkerObject(params.destination_identifier,
       params.source_identifier, params.message_type, params.message_level,
       params.message, params.line_number, params.source_url);
 }