fix(WebWorker): Add zone support to MessageBus

Closes #4053

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

@@ -1,5 +1,6 @@
 import {EventEmitter} from 'angular2/src/core/facade/async';
 import {BaseException} from 'angular2/src/core/facade/lang';
+import {NgZone} from 'angular2/src/core/zone/ng_zone';
 export {EventEmitter, Observable} from 'angular2/src/core/facade/async';
 
 function _abstract() {
@@ -13,6 +14,23 @@ function _abstract() {
  * by the corresponding MessageBusSource.
  */
 export /* abstract (with TS 1.6) */ class MessageBus implements MessageBusSource, MessageBusSink {
+  /**
+   * Sets up a new channel on the MessageBus.
+   * MUST be called before calling from or to on the channel.
+   * If runInZone is true then the source will emit events inside the angular zone
+   * and the sink will buffer messages and send only once the zone exits.
+   * if runInZone is false then the source will emit events inside the global zone
+   * and the sink will send messages immediatly.
+   */
+  initChannel(channel: string, runInZone: boolean = true): void { throw _abstract(); }
+
+  /**
+   * Assigns this bus to the given zone.
+   * Any callbacks attached to channels where runInZone was set to true on initialization
+   * will be executed in the given zone.
+   */
+  attachToZone(zone: NgZone): void { throw _abstract(); }
+
   /**
    * Returns an {@link EventEmitter} that emits every time a messsage
    * is received on the given channel.
@@ -28,6 +46,21 @@ export /* abstract (with TS 1.6) */ class MessageBus implements MessageBusSource
 }
 
 export interface MessageBusSource {
+  /**
+   * Sets up a new channel on the MessageBusSource.
+   * MUST be called before calling from on the channel.
+   * If runInZone is true then the source will emit events inside the angular zone.
+   * if runInZone is false then the source will emit events inside the global zone.
+   */
+  initChannel(channel: string, runInZone: boolean): void;
+
+  /**
+   * Assigns this source to the given zone.
+   * Any channels which are initialized with runInZone set to true will emit events that will be
+   * executed within the given zone.
+   */
+  attachToZone(zone: NgZone): void;
+
   /**
    * Returns an {@link EventEmitter} that emits every time a messsage
    * is received on the given channel.
@@ -36,6 +69,21 @@ export interface MessageBusSource {
 }
 
 export interface MessageBusSink {
+  /**
+   * Sets up a new channel on the MessageBusSink.
+   * MUST be called before calling to on the channel.
+   * If runInZone is true the sink will buffer messages and send only once the zone exits.
+   * if runInZone is false the sink will send messages immediatly.
+   */
+  initChannel(channel: string, runInZone: boolean): void;
+
+  /**
+   * Assigns this sink to the given zone.
+   * Any channels which are initilialized with runInZone set to true will wait for the given zone
+   * to exit before sending messages.
+   */
+  attachToZone(zone: NgZone): void;
+
   /**
    * Returns an {@link EventEmitter} for the given channel
    * To publish methods to that channel just call next (or add in dart) on the returned emitter