Implement native web notifications for mac

chrome/browser/notifications/message_center_notification_manager.cc

Index: chrome/browser/notifications/message_center_notification_manager.cc
diff --git a/chrome/browser/notifications/message_center_notification_manager.cc b/chrome/browser/notifications/message_center_notification_manager.cc
index b09d1826bf8e81dff258451aec3c5417843ad7fe..937b6b2b77b6998a89d77d974e5dc368d2b34315 100644
--- a/chrome/browser/notifications/message_center_notification_manager.cc
+++ b/chrome/browser/notifications/message_center_notification_manager.cc
@@ -50,8 +50,7 @@ MessageCenterNotificationManager::MessageCenterNotificationManager(
       settings_provider_(std::move(settings_provider)),
       system_observer_(this),
       stats_collector_(message_center),
-      google_now_stats_collector_(message_center)
-{
+      google_now_stats_collector_(message_center) {
   message_center_->AddObserver(this);
   message_center_->SetNotifierSettingsProvider(settings_provider_.get());
 
@@ -272,6 +271,10 @@ void MessageCenterNotificationManager::CancelAll() {
   message_center_->RemoveAllNotifications(/* by_user */ false);
 }
 
+bool MessageCenterNotificationManager::AcceptNativeNotifications() {
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // MessageCenter::Observer
 void MessageCenterNotificationManager::OnNotificationRemoved(