Remove header dependencies from sequence_checker.h to sequenced_worker_pool.h

chromeos/login/auth/login_performer.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 CHROMEOS_LOGIN_AUTH_LOGIN_PERFORMER_H_
 #define CHROMEOS_LOGIN_AUTH_LOGIN_PERFORMER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "chromeos/chromeos_export.h"
 #include "chromeos/login/auth/auth_status_consumer.h"
 #include "chromeos/login/auth/authenticator.h"
 #include "chromeos/login/auth/extended_authenticator.h"
 #include "chromeos/login/auth/user_context.h"
 #include "google_apis/gaia/google_service_auth_error.h"
 
 class AccountId;
 
+namespace base {
+class TaskRunner;
+}
+
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace content {
 class BrowserContext;
 }
 
 namespace chromeos {
 
@@ skipping 186 matching lines @@
   // Authorization mode type.
   AuthorizationMode auth_mode_;
 
   base::WeakPtrFactory<LoginPerformer> weak_factory_;
   DISALLOW_COPY_AND_ASSIGN(LoginPerformer);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_LOGIN_AUTH_LOGIN_PERFORMER_H_