Add shutdown notification and service refs to SyncServiceObserver.

ios/chrome/browser/ui/ntp/recent_tabs/synced_sessions_bridge.h

 // Copyright 2015 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 IOS_CHROME_BROWSER_UI_NTP_RECENT_TABS_SYNCED_SESSIONS_BRIDGE_H_
 #define IOS_CHROME_BROWSER_UI_NTP_RECENT_TABS_SYNCED_SESSIONS_BRIDGE_H_
 
 #import <UIKit/UIKit.h>
 
 #import "base/ios/weak_nsobject.h"
@@ skipping 17 matching lines @@
 
 // Bridge class that will notify the panel when the remote sessions content
 // change.
 class SyncedSessionsObserverBridge : public SyncObserverBridge,
                                      public SigninManagerBase::Observer {
  public:
   SyncedSessionsObserverBridge(id<SyncedSessionsObserver> owner,
                                ios::ChromeBrowserState* browserState);
   ~SyncedSessionsObserverBridge() override;
   // SyncObserverBridge implementation.
-  void OnStateChanged() override;
-  void OnSyncCycleCompleted() override;
-  void OnSyncConfigurationCompleted() override;
-  void OnForeignSessionUpdated() override;
+  void OnStateChanged(syncer::SyncService* sync) override;
+  void OnSyncCycleCompleted(syncer::SyncService* sync) override;
+  void OnSyncConfigurationCompleted(syncer::SyncService* sync) override;
+  void OnForeignSessionUpdated(syncer::SyncService* sync) override;
   // SigninManagerBase::Observer implementation.
   void GoogleSignedOut(const std::string& account_id,
                        const std::string& username) override;
   // Returns true if the first sync cycle that contains session information is
   // completed. Returns false otherwise.
   bool IsFirstSyncCycleCompleted();
 
  private:
   base::WeakNSProtocol<id<SyncedSessionsObserver>> owner_;
   SigninManager* signin_manager_;
   syncer::SyncService* sync_service_;
   ScopedObserver<SigninManagerBase, SigninManagerBase::Observer>
       signin_manager_observer_;
   // Stores whether the first sync cycle that contains session information is
   // completed.
   bool first_sync_cycle_is_completed_;
 };
 
 }  // namespace synced_sessions
 
 #endif  // IOS_CHROME_BROWSER_UI_NTP_RECENT_TABS_SYNCED_SESSIONS_BRIDGE_H_