Update OS X to use scoped_refptr<T>::get() rather than implicit "operator T*"

chrome/app/chrome_main_app_mode_mac.mm

 // 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.
 
 // On Mac, one can't make shortcuts with command-line arguments. Instead, we
 // produce small app bundles which locate the Chromium framework and load it,
 // passing the appropriate data. This is the entry point into the framework for
 // those app bundles.
 
 #import <Cocoa/Cocoa.h>
@@ skipping 93 matching lines @@
   if (!chrome::GetUserDataDirectoryForBrowserBundle(chrome_bundle,
                                                     &user_data_dir)) {
     Close();
     return;
   }
 
   base::FilePath socket_path =
       user_data_dir.Append(app_mode::kAppShimSocketName);
   IPC::ChannelHandle handle(socket_path.value());
   channel_ = new IPC::ChannelProxy(handle, IPC::Channel::MODE_NAMED_CLIENT,
-      this, g_io_thread->message_loop_proxy());
+      this, g_io_thread->message_loop_proxy().get());
 
   channel_->Send(new AppShimHostMsg_LaunchApp(
       g_info->profile_dir, g_info->app_mode_id,
       CommandLine::ForCurrentProcess()->HasSwitch(app_mode::kNoLaunchApp) ?
           apps::APP_SHIM_LAUNCH_REGISTER_ONLY : apps::APP_SHIM_LAUNCH_NORMAL));
 
   nsapp_delegate_.reset([[AppShimDelegate alloc] initWithController:this]);
   DCHECK(![NSApp delegate]);
   [NSApp setDelegate:nsapp_delegate_];
 }
@@ skipping 259 matching lines @@
   // fully initialized don't receive a reply until its run loop starts. Once
   // the reply is received, Chrome will have opened its IPC port, guaranteed.
   [ReplyEventHandler pingProcess:psn andCall:base::Bind(&OnPingChromeReply)];
 
   base::MessageLoopForUI main_message_loop;
   main_message_loop.set_thread_name("MainThread");
   base::PlatformThread::SetName("CrAppShimMain");
   main_message_loop.Run();
   return 0;
 }