Add shutdown notification and service refs to SyncServiceObserver.

ios/chrome/browser/ui/webui/sync_internals/sync_internals_message_handler.cc

 // 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.
 
 #include "ios/chrome/browser/ui/webui/sync_internals/sync_internals_message_handler.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "base/values.h"
@@ skipping 139 matching lines @@
 }
 
 void SyncInternalsMessageHandler::OnReceivedAllNodes(
     int request_id,
     std::unique_ptr<base::ListValue> nodes) {
   base::FundamentalValue id(request_id);
   web_ui()->CallJavascriptFunction(syncer::sync_ui_util::kGetAllNodesCallback,
                                    id, *nodes);
 }
 
-void SyncInternalsMessageHandler::OnStateChanged() {
+void SyncInternalsMessageHandler::OnStateChanged(syncer::SyncService* sync) {
   SendAboutInfo();
 }
 
 void SyncInternalsMessageHandler::OnProtocolEvent(
     const syncer::ProtocolEvent& event) {
   std::unique_ptr<base::DictionaryValue> value(
       syncer::ProtocolEvent::ToValue(event));
   web_ui()->CallJavascriptFunction(
       syncer::sync_ui_util::kDispatchEvent,
       base::StringValue(syncer::sync_ui_util::kOnProtocolEvent), *value);
@@ skipping 52 matching lines @@
       base::StringValue(syncer::sync_ui_util::kOnAboutInfoUpdated), *value);
 }
 
 // Gets the SyncService of the underlying original profile. May return null.
 syncer::SyncService* SyncInternalsMessageHandler::GetSyncService() {
   ios::ChromeBrowserState* browser_state =
       ios::ChromeBrowserState::FromWebUIIOS(web_ui());
   return IOSChromeProfileSyncServiceFactory::GetForBrowserState(
       browser_state->GetOriginalChromeBrowserState());
 }