chore: upgrade to new Zone.js API v0.6.2

BREAKING CHANGE

Removed deprecated API from NgZone
- `NgZone.overrideOnTurnStart`
- `NgZone.overrideOnTurnDone`
- `NgZone.overrideOnEventDone`
- `NgZone.overrideOnErrorHandler`

Rename NgZone API
- `NgZone.onTurnStart` => `NgZone.onUnstable`
- `NgZone.onTurnDone` => `NgZone.onMicrotaskEmpty`
- `NgZone.onEventDone` => `NgZone.onStable`

Closes #7345

modules/angular2/src/web_workers/shared/generic_message_bus.dart

@@ -46,7 +46,7 @@ abstract class GenericMessageBusSink implements MessageBusSink {
   void attachToZone(NgZone zone) {
     _zone = zone;
     _zone.runOutsideAngular(() {
-      _zone.onEventDone.listen((_) {
+      _zone.onStable.listen((_) {
         if (_messageBuffer.length > 0) {
           sendMessages(_messageBuffer);
           _messageBuffer.clear();

modules/angular2/src/web_workers/shared/post_message_bus.ts

@@ -22,7 +22,7 @@ export class PostMessageBusSink implements MessageBusSink {
   attachToZone(zone: NgZone): void {
     this._zone = zone;
     this._zone.runOutsideAngular(() => {
-      ObservableWrapper.subscribe(this._zone.onEventDone, (_) => { this._handleOnEventDone(); });
+      ObservableWrapper.subscribe(this._zone.onStable, (_) => { this._handleOnEventDone(); });
     });
   }