feat(WebWorker) Add channel support to MessageBus

closes #3661 and #3686

modules/examples/src/web_workers/images/services/bitmap.dart

@@ -5,19 +5,19 @@ import 'dart:typed_data';
 
 // TODO(jteplitz602) Implement this class #3493
 class BitmapService {
-  ImageData applySepia (ImageData imageData) {
+  ImageData applySepia(ImageData imageData) {
     return null;
   }
 
-  String arrayBufferToDataUri (Uint8ClampedList data) {
+  String arrayBufferToDataUri(Uint8ClampedList data) {
     return null;
   }
 
-  ImageData convertToImageData (ByteBuffer buffer) {
+  ImageData convertToImageData(ByteBuffer buffer) {
     return null;
   }
 
-  String toDataUri (ImageData imageData) {
+  String toDataUri(ImageData imageData) {
     return null;
   }
 }