refactor(test): Remove unnecessary noSuchMethod

Remove trivial implementations in many spy objects which just calls the
parent's `noSuchMethod`.

Closes #6410

Closes #6491

modules/angular2/test/web_workers/debug_tools/web_socket_message_bus_spec.dart

@@ -60,15 +60,9 @@ main() {
 @proxy
 class SpyMessageEvent extends SpyObject implements MessageEvent {
   SpyMessageEvent() : super(SpyMessageEvent);
-  noSuchMethod(m) {
-    return super.noSuchMethod(m);
-  }
 }
 
 @proxy
 class SpyWebSocket extends SpyObject implements WebSocket {
   SpyWebSocket() : super(SpyWebSocket);
-  noSuchMethod(m) {
-    return super.noSuchMethod(m);
-  }
 }