Convert utility process extension ParseUpdate IPC to mojo

extensions/shell/utility/shell_content_utility_client.h

 // Copyright 2014 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 EXTENSIONS_SHELL_UTILITY_SHELL_CONTENT_UTILITY_CLIENT_H_
 #define EXTENSIONS_SHELL_UTILITY_SHELL_CONTENT_UTILITY_CLIENT_H_
 
 #include "content/public/utility/content_utility_client.h"
 #include "extensions/utility/utility_handler.h"
 
 namespace extensions {
 
 class ShellContentUtilityClient : public content::ContentUtilityClient {
  public:
   ShellContentUtilityClient();
   ~ShellContentUtilityClient() override;
 
   // content::ContentUtilityClient:
   void UtilityThreadStarted() override;
-  bool OnMessageReceived(const IPC::Message& message) override;
-
- private:
-  UtilityHandler utility_handler_;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_SHELL_UTILITY_SHELL_CONTENT_UTILITY_CLIENT_H_