Change ChildProcess::set_main_thread registration to occur inside the RenderThreadImpl::Init method.

content/renderer/render_thread_impl.cc

 // Copyright (c) 2012 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 "content/renderer/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <vector>
@@ skipping 168 matching lines @@
 #endif
 
   lazy_tls.Pointer()->Set(this);
 #if defined(OS_WIN)
   // If you are running plugins in this thread you need COM active but in
   // the normal case you don't.
   if (RenderProcessImpl::InProcessPlugins())
     initialize_com_.reset(new base::win::ScopedCOMInitializer());
 #endif
 
+  // Register this object as the main thread.
+  ChildProcess::current()->set_main_thread(this);
+
   // In single process the single process is all there is.
   suspend_webkit_shared_timer_ = true;
   notify_webkit_of_modal_loop_ = true;
   plugin_refresh_allowed_ = true;
   widget_count_ = 0;
   hidden_widget_count_ = 0;
   idle_notification_delay_in_ms_ = kInitialIdleHandlerDelayMs;
   idle_notifications_to_skip_ = 0;
   compositor_initialized_ = false;
 
@@ skipping 654 matching lines @@
 
 scoped_refptr<base::MessageLoopProxy>
 RenderThreadImpl::GetFileThreadMessageLoopProxy() {
   DCHECK(message_loop() == MessageLoop::current());
   if (!file_thread_.get()) {
     file_thread_.reset(new base::Thread("Renderer::FILE"));
     file_thread_->Start();
   }
   return file_thread_->message_loop_proxy();
 }