Bug 1696347 - Remove redundant nullptr checks of return value of infallible new in dom/workers. r=dom-worker-reviewers,janv

Differential Revision: https://phabricator.services.mozilla.com/D107179

dom/workers/WorkerRunnable.cpp

@@ -709,9 +709,6 @@ bool WorkerDebuggeeRunnable::PreDispatch(WorkerPrivate* aWorkerPrivate) {
     }
 
     mSender = new ThreadSafeWorkerRef(strongRef);
-    if (!mSender) {
-      return false;
-    }
   }
 
   return WorkerRunnable::PreDispatch(aWorkerPrivate);