Bug 1450644 - WorkerRef should make APIs able to work until the worker is completely terminated - part 2 - BroadcastChannel, r=asuth

dom/broadcastchannel/BroadcastChannel.cpp

@@ -311,15 +311,15 @@ BroadcastChannel::Constructor(const GlobalObject& aGlobal,
     // We are already shutting down the worker. Let's return a non-active
     // object.
     if (NS_WARN_IF(!workerRef)) {
-      bc->mState = StateClosed;
-      return bc.forget();
+      aRv.Throw(NS_ERROR_FAILURE);
+      return nullptr;
     }
 
     RefPtr<ThreadSafeWorkerRef> tsr = new ThreadSafeWorkerRef(workerRef);
 
     RefPtr<InitializeRunnable> runnable =
       new InitializeRunnable(tsr, origin, principalInfo, aRv);
-    runnable->Dispatch(Closing, aRv);
+    runnable->Dispatch(Canceling, aRv);
     if (aRv.Failed()) {
       return nullptr;
     }

dom/broadcastchannel/BroadcastChannel.h

@@ -68,11 +68,6 @@ private:
 
   ~BroadcastChannel();
 
-  void PostMessageData(BroadcastChannelMessage* aData);
-
-  void PostMessageInternal(JSContext* aCx, JS::Handle<JS::Value> aMessage,
-                           ErrorResult& aRv);
-
   void RemoveDocFromBFCache();
 
   void DisconnectFromOwner() override;

testing/web-platform/tests/webmessaging/broadcastchannel/workers.html

@@ -121,4 +121,21 @@ async_test(t => {
   }
 }, 'BroadcastChannel created after a worker self.close()');
 
+async_test(t => {
+  function workerCode() {
+    close();
+    var bc = new BroadcastChannel('worker-test-after-close');
+    bc.postMessage(true);
+  }
+
+  var bc = new BroadcastChannel('worker-test-after-close');
+  bc.onmessage = function(e) {
+    assert_true(e.data, "BroadcastChannel created on worker shutdown.");
+    t.done();
+  }
+
+  var workerBlob = new Blob([workerCode.toString() + ";workerCode();"], {type:"application/javascript"});
+  new Worker(URL.createObjectURL(workerBlob));
+}, 'BroadcastChannel used after a worker self.close()');
+
 </script>