Use Mojo Permission Service when requesting Notifications permission.

content/child/notifications/notification_dispatcher.cc

Index: content/child/notifications/notification_dispatcher.cc
diff --git a/content/child/notifications/notification_dispatcher.cc b/content/child/notifications/notification_dispatcher.cc
index 9401903333dda9ce8d2c45aea5e9bf05e2c81ca6..a9a5daab224c3c0c887a34a26dd34f90f7f5c38a 100644
--- a/content/child/notifications/notification_dispatcher.cc
+++ b/content/child/notifications/notification_dispatcher.cc
@@ -63,11 +63,7 @@ bool NotificationDispatcher::OnMessageReceived(const IPC::Message& msg) {
 }
 
 bool NotificationDispatcher::ShouldHandleMessage(const IPC::Message& msg) {
-  // The thread-safe message filter is responsible for handling all the messages
-  // except for the routed permission-request-completed message, which will be
-  // picked up by the RenderFrameImpl instead.
-  return IPC_MESSAGE_CLASS(msg) == PlatformNotificationMsgStart &&
-         msg.type() != PlatformNotificationMsg_PermissionRequestComplete::ID;
+  return IPC_MESSAGE_CLASS(msg) == PlatformNotificationMsgStart;
 }
 
 }  // namespace content