[Sync] Move sync error controller to sync driver component

chrome/browser/sync/sync_error_controller.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_SYNC_SYNC_ERROR_CONTROLLER_H_
-#define CHROME_BROWSER_SYNC_SYNC_ERROR_CONTROLLER_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/observer_list.h"
-#include "components/sync_driver/sync_service_observer.h"
-
-class Profile;
-class ProfileSyncService;
-
-// Keep track of sync errors and expose them to observers in the UI.
-class SyncErrorController : public sync_driver::SyncServiceObserver {
- public:
-  // The observer class for SyncErrorController lets the controller notify
-  // observers when an error arises or changes.
-  class Observer {
-   public:
-    virtual ~Observer() {}
-    virtual void OnErrorChanged() = 0;
-  };
-
-  explicit SyncErrorController(ProfileSyncService* service);
-  ~SyncErrorController() override;
-
-  // True if there exists an error worth elevating to the user.
-  bool HasError();
-
-  void AddObserver(Observer* observer);
-  void RemoveObserver(Observer* observer);
-
-  // sync_driver::SyncServiceObserver:
-  void OnStateChanged() override;
-
- private:
-  ProfileSyncService* service_;
-  base::ObserverList<Observer, true> observer_list_;
-
-  DISALLOW_COPY_AND_ASSIGN(SyncErrorController);
-};
-
-#endif  // CHROME_BROWSER_SYNC_SYNC_ERROR_CONTROLLER_H_