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

content/public/child/child_thread.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_CHILD_CHILD_THREAD_H_
 #define CONTENT_PUBLIC_CHILD_CHILD_THREAD_H_
 
-#include <memory>
 #include <string>
 
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "content/common/content_export.h"
 #include "ipc/ipc_sender.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
 namespace base {
 struct UserMetricsAction;
 }
 
 namespace shell {
 class InterfaceProvider;
 class InterfaceRegistry;
 }
 
 namespace content {
 
-class ConnectionFilter;
-class MojoShellConnection;
+  class MojoShellConnection;
 
 // An abstract base class that contains logic shared between most child
 // processes of the embedder.
 class CONTENT_EXPORT ChildThread : public IPC::Sender {
  public:
   // Returns the one child thread for this process.  Note that this can only be
   // accessed when running on the child thread itself.
   static ChildThread* Get();
 
   ~ChildThread() override {}
@@ skipping 35 matching lines @@
   virtual shell::InterfaceRegistry* GetInterfaceRegistry() = 0;
 
   // Returns the InterfaceProvider that this process can use to bind
   // interfaces exposed to it by the browser.
   virtual shell::InterfaceProvider* GetRemoteInterfaces() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_CHILD_CHILD_THREAD_H_