Add shutdown notification and service refs to SyncServiceObserver.

ios/chrome/browser/ui/webui/sync_internals/sync_internals_message_handler.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_WEBUI_SYNC_INTERNALS_SYNC_INTERNALS_MESSAGE_HANDLER_H_
 #define IOS_CHROME_BROWSER_UI_WEBUI_SYNC_INTERNALS_SYNC_INTERNALS_MESSAGE_HANDLER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 43 matching lines @@
 
   // syncer::JsEventHandler implementation.
   void HandleJsEvent(const std::string& name,
                      const syncer::JsEventDetails& details) override;
 
   // Callback used in GetAllNodes.
   void OnReceivedAllNodes(int request_id,
                           std::unique_ptr<base::ListValue> nodes);
 
   // syncer::SyncServiceObserver implementation.
-  void OnStateChanged() override;
+  void OnStateChanged(syncer::SyncService* sync) override;
 
   // ProtocolEventObserver implementation.
   void OnProtocolEvent(const syncer::ProtocolEvent& e) override;
 
   // TypeDebugInfoObserver implementation.
   void OnCommitCountersUpdated(syncer::ModelType type,
                                const syncer::CommitCounters& counters) override;
   void OnUpdateCountersUpdated(syncer::ModelType type,
                                const syncer::UpdateCounters& counters) override;
   void OnStatusCountersUpdated(syncer::ModelType type,
@@ skipping 23 matching lines @@
   // A flag used to prevent double-registration as TypeDebugInfoObserver with
   // ProfileSyncService.
   bool is_registered_for_counters_;
 
   base::WeakPtrFactory<SyncInternalsMessageHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncInternalsMessageHandler);
 };
 
 #endif  // IOS_CHROME_BROWSER_UI_WEBUI_SYNC_INTERNALS_SYNC_INTERNALS_MESSAGE_HANDLER_H_