Turn FaviconClient into a Keyed service.

components/favicon/core/browser/favicon_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 COMPONENTS_FAVICON_CORE_BROWSER_FAVICON_CLIENT_H_
 #define COMPONENTS_FAVICON_CORE_BROWSER_FAVICON_CLIENT_H_
 
+#include "components/keyed_service/core/keyed_service.h"
+
 class FaviconService;
 class GURL;
 
 // This class abstracts operations that depend on the embedder's environment,
 // e.g. Chrome.
-class FaviconClient {
+class FaviconClient : public KeyedService {
  public:
   virtual ~FaviconClient() {};
 
   virtual FaviconService* GetFaviconService() = 0;
 
   // Returns true if the specified URL is bookmarked.
   virtual bool IsBookmarked(const GURL& url) = 0;
 };
 
 #endif  // COMPONENTS_FAVICON_CORE_BROWSER_FAVICON_CLIENT_H_