Eliminate NOTIFICATION_HISTORY_LOADED notification

chrome/browser/ui/cocoa/history_menu_bridge.h

Index: chrome/browser/ui/cocoa/history_menu_bridge.h
diff --git a/chrome/browser/ui/cocoa/history_menu_bridge.h b/chrome/browser/ui/cocoa/history_menu_bridge.h
index 70f5c4d3eed41789e895012427086a6bebd43729..9aa493f8f6b25c3b6fef3573469eddba60535480 100644
--- a/chrome/browser/ui/cocoa/history_menu_bridge.h
+++ b/chrome/browser/ui/cocoa/history_menu_bridge.h
@@ -11,6 +11,7 @@
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/ref_counted.h"
+#include "base/scoped_observer.h"
 #include "base/task/cancelable_task_tracker.h"
 #import "chrome/browser/favicon/favicon_service.h"
 #include "chrome/browser/history/history_service.h"
@@ -147,6 +148,7 @@ class HistoryMenuBridge : public content::NotificationObserver,
                     const history::URLRow& row,
                     const history::RedirectList& redirects,
                     base::Time visit_time) override;
+  void OnHistoryServiceLoaded(HistoryService* service) override;
 
   // Looks up an NSMenuItem in the |menu_item_map_| and returns the
   // corresponding HistoryItem.
@@ -238,6 +240,9 @@ class HistoryMenuBridge : public content::NotificationObserver,
   // The default favicon if a HistoryItem does not have one.
   base::scoped_nsobject<NSImage> default_favicon_;
 
+  ScopedObserver<HistoryService, HistoryServiceObserver>
+      history_service_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(HistoryMenuBridge);
 };