Bug 1578394 - MessageTask::GetType should actually return the message type, r=nika

Differential Revision: https://phabricator.services.mozilla.com/D44471

--HG--
extra : moz-landing-system : lando

ipc/glue/MessageChannel.cpp

@@ -2067,6 +2067,8 @@ MessageChannel::MessageTask::GetType(uint32_t* aType) {
     // has been.
     return NS_ERROR_FAILURE;
   }
+
+  *aType = Msg().type();
   return NS_OK;
 }