Revert r21117 as it caused reliability failures....

chrome/worker/worker_main.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 "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
 #include "base/system_monitor.h"
 #include "chrome/common/child_process.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/logging_chrome.h"
 #include "chrome/common/main_function_params.h"
 #include "chrome/worker/worker_thread.h"
 
 #if defined(OS_WIN)
 #include "chrome/common/sandbox_init_wrapper.h"
 #include "sandbox/src/sandbox.h"
 #endif
 
 // Mainline routine for running as the worker process.
 int WorkerMain(const MainFunctionParams& parameters) {
-  // The main message loop of the worker process.
-  MessageLoop main_message_loop;
+  // The main thread of the render process.
+  MessageLoopForIO main_message_loop;
   std::wstring app_name = chrome::kBrowserAppName;
   PlatformThread::SetName(WideToASCII(app_name + L"_WorkerMain").c_str());
 
   // Initialize the SystemMonitor
   base::SystemMonitor::Start();
 
-  ChildProcess worker_process;
-  worker_process.set_main_thread(new WorkerThread());
+  ChildProcess worker_process(new WorkerThread());
 #if defined(OS_WIN)
   sandbox::TargetServices* target_services =
       parameters.sandbox_info_.TargetServices();
   if (!target_services)
     return false;
 
   target_services->LowerToken();
 #endif
 
   // Load the accelerator table from the browser executable and tell the
   // message loop to use it when translating messages.
   MessageLoop::current()->Run();
 
   return 0;
 }