[Sync] Move the last things out of core/.

components/sync/core/sync_auth_provider.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_SYNC_CORE_SYNC_AUTH_PROVIDER_H_
-#define COMPONENTS_SYNC_CORE_SYNC_AUTH_PROVIDER_H_
-
-#include <string>
-
-#include "base/callback.h"
-
-class GoogleServiceAuthError;
-
-namespace syncer {
-
-// SyncAuthProvider is interface to access token related functions from sync
-// engine.
-class SyncAuthProvider {
- public:
-  typedef base::Callback<void(const GoogleServiceAuthError& error,
-                              const std::string& token)>
-      RequestTokenCallback;
-
-  virtual ~SyncAuthProvider() {}
-
-  // Request access token for sync. Callback will be called with error and
-  // access token. If error is anything other than NONE then token is invalid.
-  virtual void RequestAccessToken(const RequestTokenCallback& callback) = 0;
-
-  // Invalidate access token that was rejected by sync server.
-  virtual void InvalidateAccessToken(const std::string& token) = 0;
-};
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_SYNC_CORE_SYNC_AUTH_PROVIDER_H_