Revert of Move content's shell connections to the IO thread

content/browser/browser_main_loop.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/browser/browser_main_loop.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 260 matching lines @@
                       GLibLogHandler,
                       NULL);
   }
 }
 #endif  // defined(USE_GLIB)
 
 #if defined(MOJO_SHELL_CLIENT) && defined(USE_AURA)
 void WaitForMojoShellInitialize() {
   // TODO(rockot): Remove this. http://crbug.com/594852.
   base::RunLoop wait_loop;
-  MojoShellConnection::GetForProcess()->SetInitializeHandler(
-      wait_loop.QuitClosure());
+  MojoShellConnection::GetForProcess()->GetShellConnection()->
+      set_initialize_handler(wait_loop.QuitClosure());
   wait_loop.Run();
 }
 #endif  // defined(MOJO_SHELL_CLIENT) && defined(USE_AURA)
 
 void OnStoppedStartupTracing(const base::FilePath& trace_file) {
   VLOG(0) << "Completed startup tracing to " << trace_file.value();
 }
 
 // Disable optimizations for this block of functions so the compiler doesn't
 // merge them all together. This makes it possible to tell what thread was
@@ skipping 1214 matching lines @@
     scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner =
         audio_thread_->task_runner();
     audio_manager_ = media::AudioManager::Create(std::move(audio_task_runner),
                                                  std::move(worker_task_runner),
                                                  MediaInternals::GetInstance());
   }
   CHECK(audio_manager_);
 }
 
 }  // namespace content