Add ExtensionsApiClient interface, use it in the storage API SettingsFrontend

chrome/browser/extensions/api/storage/syncable_settings_storage.cc

 // 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.
 
 #include "chrome/browser/extensions/api/storage/syncable_settings_storage.h"
 
 #include "base/strings/stringprintf.h"
-#include "chrome/browser/extensions/api/storage/settings_namespace.h"
 #include "chrome/browser/extensions/api/storage/settings_sync_processor.h"
 #include "chrome/browser/extensions/api/storage/settings_sync_util.h"
 #include "content/public/browser/browser_thread.h"
+#include "extensions/browser/api/storage/settings_namespace.h"
 #include "sync/api/sync_data.h"
 #include "sync/protocol/extension_setting_specifics.pb.h"
 
 namespace extensions {
 
 using content::BrowserThread;
 
 SyncableSettingsStorage::SyncableSettingsStorage(
     const scoped_refptr<ObserverListThreadSafe<SettingsObserver> >&
         observers,
@@ skipping 394 matching lines @@
         syncer::SyncError::DATATYPE_ERROR,
         base::StringPrintf("Error pushing sync remove to local settings: %s",
             result->error().message.c_str()),
         sync_processor_->type());
   }
   changes->push_back(ValueStoreChange(key, old_value, NULL));
   return syncer::SyncError();
 }
 
 }  // namespace extensions