content: Cleanup class/struct forward declarations

content/public/utility/content_utility_client.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_UTILITY_CONTENT_UTILITY_CLIENT_H_
 #define CONTENT_PUBLIC_UTILITY_CONTENT_UTILITY_CLIENT_H_
 
 #include <map>
 #include <memory>
 
 #include "base/callback_forward.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/service_info.h"
 
 namespace service_manager {
 class InterfaceRegistry;
-class Service;
 }
 
 namespace content {
 
 // Embedder API for participating in renderer logic.
 class CONTENT_EXPORT ContentUtilityClient {
  public:
   using StaticServiceMap = std::map<std::string, ServiceInfo>;
 
   virtual ~ContentUtilityClient() {}
 
   // Notifies us that the UtilityThread has been created.
   virtual void UtilityThreadStarted() {}
 
   // Allows the embedder to filter messages.
   virtual bool OnMessageReceived(const IPC::Message& message);
 
   // Allows the client to expose interfaces from this utility process to the
   // browser process via |registry|.
   virtual void ExposeInterfacesToBrowser(
       service_manager::InterfaceRegistry* registry) {}
 
   virtual void RegisterServices(StaticServiceMap* services) {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_UTILITY_CONTENT_UTILITY_CLIENT_H_