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

content/child/background_sync/background_sync_provider.cc

 // Copyright 2015 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/child/background_sync/background_sync_provider.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_local.h"
 #include "content/child/background_sync/background_sync_type_converters.h"
 #include "content/child/child_thread_impl.h"
 #include "content/child/service_worker/web_service_worker_registration_impl.h"
-#include "services/shell/public/cpp/interface_provider.h"
 #include "third_party/WebKit/public/platform/modules/background_sync/WebSyncError.h"
 #include "third_party/WebKit/public/platform/modules/background_sync/WebSyncRegistration.h"
 
 using base::LazyInstance;
 using base::ThreadLocalPointer;
 
 namespace content {
 namespace {
 
 // Returns the id of the given |service_worker_registration|, which
@@ skipping 183 matching lines @@
     mojo::InterfaceRequest<blink::mojom::BackgroundSyncService> request =
         mojo::GetProxy(&background_sync_service_);
     main_thread_task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&ConnectToServiceOnMainThread, base::Passed(&request)));
   }
   return background_sync_service_;
 }
 
 }  // namespace content