Add shutdown notification and service refs to SyncServiceObserver.

chrome/browser/ui/webui/options/clear_browser_data_handler.cc

Index: chrome/browser/ui/webui/options/clear_browser_data_handler.cc
diff --git a/chrome/browser/ui/webui/options/clear_browser_data_handler.cc b/chrome/browser/ui/webui/options/clear_browser_data_handler.cc
index 0d7767128d979c0671e706dc878005b1a2bc1c33..e159a35149a771adab1bb97e9cf3217f2f57b843 100644
--- a/chrome/browser/ui/webui/options/clear_browser_data_handler.cc
+++ b/chrome/browser/ui/webui/options/clear_browser_data_handler.cc
@@ -391,7 +391,11 @@ void ClearBrowserDataHandler::UpdateCounterText(
       base::StringValue(GetChromeCounterTextFromResult(result.get())));
 }
 
-void ClearBrowserDataHandler::OnStateChanged() {
+void ClearBrowserDataHandler::OnStateChanged(syncer::SyncService* sync) {
+  UpdateSyncState();
+}
+
+void ClearBrowserDataHandler::UpdateSyncState() {
   web_ui()->CallJavascriptFunctionUnsafe(
       "ClearBrowserDataOverlay.updateSyncWarningAndHistoryFooter",
       base::FundamentalValue(sync_service_ && sync_service_->IsSyncActive()),
@@ -423,7 +427,7 @@ void ClearBrowserDataHandler::RefreshHistoryNotice() {
 
 void ClearBrowserDataHandler::UpdateHistoryNotice(bool show) {
   should_show_history_notice_ = show;
-  OnStateChanged();
+  UpdateSyncState();
 
   UMA_HISTOGRAM_BOOLEAN(
       "History.ClearBrowsingData.HistoryNoticeShownInFooterWhenUpdated",