Hook up LocalNtpSource to OneGoogleBarService

chrome/browser/search/one_google_bar/one_google_bar_service_observer.h

Index: chrome/browser/search/one_google_bar/one_google_bar_service_observer.h
diff --git a/chrome/browser/search/one_google_bar/one_google_bar_service_observer.h b/chrome/browser/search/one_google_bar/one_google_bar_service_observer.h
index 948023109622acd285e389f8e5d6f63514da9a6f..3437724ca9bec3e226e2b39782169e737b111fbb 100644
--- a/chrome/browser/search/one_google_bar/one_google_bar_service_observer.h
+++ b/chrome/browser/search/one_google_bar/one_google_bar_service_observer.h
@@ -8,9 +8,20 @@
 // Observer for OneGoogleBarService.
 class OneGoogleBarServiceObserver {
  public:
-  // Called when the OneGoogleBarData changes. You can get the new data via
+  // Called when the OneGoogleBarData changes, including changes between null
+  // and non-null. You can get the new data via
   // OneGoogleBarService::one_google_bar_data().
   virtual void OnOneGoogleBarDataChanged() = 0;
+
+  // Called when an attempt to fetch the OneGoogleBarData failed. Note that if
+  // there was cached data before the failed fetch attempt, then
+  // OnOneGoogleBarDataChanged gets called first.
+  virtual void OnOneGoogleBarFetchFailed() {}
+
+  // Called when the OneGoogleBarService is shutting down. Observers that might
+  // outlive the service should use this to unregister themselves, and clear out
+  // any pointers to the service they might hold.
+  virtual void OnOneGoogleBarServiceShuttingDown() {}
 };
 
 #endif  // CHROME_BROWSER_SEARCH_ONE_GOOGLE_BAR_ONE_GOOGLE_BAR_SERVICE_OBSERVER_H_