plugins: use OnChannelError to detect when the channel goes away

chrome/browser/worker_host/worker_process_host.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/browser/worker_host/worker_process_host.h"
 
 #include <set>
 
 #include "base/command_line.h"
 #include "base/debug_util.h"
+#include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/child_process_security_policy.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/worker_host/worker_service.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/debug_flags.h"
 #include "chrome/common/process_watcher.h"
@@ skipping 197 matching lines @@
 }
 
 void WorkerProcessHost::OnCancelCreateDedicatedWorker(int route_id) {
   WorkerService::GetInstance()->CancelCreateDedicatedWorker(
       GetProcessId(), route_id);
 }
 
 void WorkerProcessHost::OnForwardToWorker(const IPC::Message& message) {
   WorkerService::GetInstance()->ForwardMessage(message, GetProcessId());
 }