Bug 1141026 - BroadcastChannel should throw if it fails registering the worker feature, r=smaug

dom/broadcastchannel/BroadcastChannel.cpp

@@ -513,6 +513,8 @@ BroadcastChannel::Constructor(const GlobalObject& aGlobal,
     JSContext* cx = workerPrivate->GetJSContext();
     if (NS_WARN_IF(!workerPrivate->AddFeature(cx, bc->mWorkerFeature))) {
       NS_WARNING("Failed to register the BroadcastChannel worker feature.");
+      bc->mWorkerFeature = nullptr;
+      aRv.Throw(NS_ERROR_FAILURE);
       return nullptr;
     }
   }

dom/workers/WorkerPrivate.cpp

@@ -5415,7 +5415,7 @@ WorkerPrivate::AddFeature(JSContext* aCx, WorkerFeature* aFeature)
     }
   }
 
-  NS_ASSERTION(!mFeatures.Contains(aFeature), "Already know about this one!");
+  MOZ_ASSERT(!mFeatures.Contains(aFeature), "Already know about this one!");
   mFeatures.AppendElement(aFeature);
 
   return mFeatures.Length() == 1 ?
@@ -5428,7 +5428,7 @@ WorkerPrivate::RemoveFeature(JSContext* aCx, WorkerFeature* aFeature)
 {
   AssertIsOnWorkerThread();
 
-  NS_ASSERTION(mFeatures.Contains(aFeature), "Didn't know about this one!");
+  MOZ_ASSERT(mFeatures.Contains(aFeature), "Didn't know about this one!");
   mFeatures.RemoveElement(aFeature);
 
   if (mFeatures.IsEmpty() && !ModifyBusyCountFromWorker(aCx, false)) {