Revert of Add ExtensionsApiClient interface, use it in the storage API SettingsFrontend

chrome/browser/extensions/api/chrome_extensions_api_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 CHROME_BROWSER_EXTENSIONS_API_CHROME_EXTENSIONS_API_CLIENT_H_
-#define CHROME_BROWSER_EXTENSIONS_API_CHROME_EXTENSIONS_API_CLIENT_H_
-
-#include "base/compiler_specific.h"
-#include "extensions/browser/api/extensions_api_client.h"
-
-namespace extensions {
-
-// Extra support for extensions APIs in Chrome.
-class ChromeExtensionsAPIClient : public ExtensionsAPIClient {
- public:
-  ChromeExtensionsAPIClient();
-  virtual ~ChromeExtensionsAPIClient();
-
-  // ExtensionsApiClient implementation.
-  virtual void AddAdditionalValueStoreCaches(
-      content::BrowserContext* context,
-      const scoped_refptr<SettingsStorageFactory>& factory,
-      const scoped_refptr<ObserverListThreadSafe<SettingsObserver> >& observers,
-      std::map<settings_namespace::Namespace, ValueStoreCache*>* caches)
-      OVERRIDE;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ChromeExtensionsAPIClient);
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_API_CHROME_EXTENSIONS_API_CLIENT_H_