Eliminate NOTIFICATION_HISTORY_LOADED notification

chrome/browser/ui/omnibox/omnibox_view_browsertest.cc

Index: chrome/browser/ui/omnibox/omnibox_view_browsertest.cc
diff --git a/chrome/browser/ui/omnibox/omnibox_view_browsertest.cc b/chrome/browser/ui/omnibox/omnibox_view_browsertest.cc
index 4a0f5c1a339d6e4a7506e04ddb8a2f17a5190113..4e970e065c87ce95a0c696052f140bdc8530d3b6 100644
--- a/chrome/browser/ui/omnibox/omnibox_view_browsertest.cc
+++ b/chrome/browser/ui/omnibox/omnibox_view_browsertest.cc
@@ -137,7 +137,16 @@ const int kCtrlOrCmdMask = ui::EF_CONTROL_DOWN;
 }  // namespace
 
 class OmniboxViewTest : public InProcessBrowserTest,
-                        public content::NotificationObserver {
+                        public content::NotificationObserver,
+                        public history::HistoryServiceObserver {
+ public:
+  OmniboxViewTest() : observer_(this) {}
+
+  // history::HisoryServiceObserver
+  void OnHistoryServiceLoaded(HistoryService* history_service) override {
+    base::MessageLoop::current()->Quit();
+  }
+
  protected:
   void SetUpOnMainThread() override {
     ASSERT_TRUE(ui_test_utils::BringBrowserWindowToFront(browser()));
@@ -282,9 +291,7 @@ class OmniboxViewTest : public InProcessBrowserTest,
     ASSERT_TRUE(history_service);
 
     if (!history_service->BackendLoaded()) {
-      content::NotificationRegistrar registrar;
-      registrar.Add(this, chrome::NOTIFICATION_HISTORY_LOADED,
-                    content::Source<Profile>(profile));
+      observer_.Add(history_service);
       content::RunMessageLoop();
     }
 
@@ -346,7 +353,6 @@ class OmniboxViewTest : public InProcessBrowserTest,
       case content::NOTIFICATION_WEB_CONTENTS_DESTROYED:
       case chrome::NOTIFICATION_TAB_PARENTED:
       case chrome::NOTIFICATION_AUTOCOMPLETE_CONTROLLER_RESULT_READY:
-      case chrome::NOTIFICATION_HISTORY_LOADED:
       case chrome::NOTIFICATION_HISTORY_URLS_MODIFIED:
         break;
       default:
@@ -354,6 +360,9 @@ class OmniboxViewTest : public InProcessBrowserTest,
     }
     base::MessageLoop::current()->Quit();
   }
+
+ private:
+  ScopedObserver<HistoryService, OmniboxViewTest> observer_;
 };
 
 // Test if ctrl-* accelerators are workable in omnibox.