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

components/sync/engine/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_
+#ifndef COMPONENTS_SYNC_ENGINE_SYNC_AUTH_PROVIDER_H_
+#define COMPONENTS_SYNC_ENGINE_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_
+#endif  // COMPONENTS_SYNC_ENGINE_SYNC_AUTH_PROVIDER_H_