[MediaSession] Add playbackState attribute to Blink MediaSession and use it to determine playback s…

third_party/WebKit/LayoutTests/media/mediasession/mojo/resources/mediasessionservice-mock.js

 /*
  * mediasessionservice-mock contains a mock implementation of MediaSessionService.
  */
 
 "use strict";
 
 var MediaSessionAction;
+var MediaSessionPlaybackState;
 
 function mojoString16ToJS(mojoString16) {
   return String.fromCharCode.apply(null, mojoString16.data);
 }
 
 function mojoImageToJS(mojoImage) {
   var src = mojoImage.src.url;
   var type = mojoString16ToJS(mojoImage.type);
   var sizes = "";
   for (var i = 0; i < mojoImage.sizes.length; i++) {
@@ skipping 21 matching lines @@
 }
 
 let mediaSessionServiceMock = loadMojoModules(
     'mediaSessionServiceMock',
     ['third_party/WebKit/public/platform/modules/mediasession/media_session.mojom',
      'mojo/public/js/router',
     ]).then(mojo => {
       let [mediaSessionService, router] = mojo.modules;
 
       MediaSessionAction = mediaSessionService.MediaSessionAction;
+      MediaSessionPlaybackState = mediaSessionService.MediaSessionPlaybackState;
 
       class MediaSessionServiceMock {
         constructor(interfaceProvider) {
           interfaceProvider.addInterfaceOverrideForTesting(
               mediaSessionService.MediaSessionService.name,
               handle => this.connectMediaSessionService_(handle));
           this.interfaceProvider_ = interfaceProvider;
           this.pendingResponse_ = null;
         }
 
         connectMediaSessionService_(handle) {
           this.mediaSessionServiceStub_ = new mediaSessionService.MediaSessionService.stubClass(this);
           this.mediaSessionServiceRouter_ = new router.Router(handle);
           this.mediaSessionServiceRouter_.setIncomingReceiver(this.mediaSessionServiceStub_);
         }
 
         setMetadata(metadata) {
           if (!!this.metadataCallback_)
             this.metadataCallback_(mojoMetadataToJS(metadata));
         }
 
         setMetadataCallback(callback) {
           this.metadataCallback_ = callback;
         }
 
+        setPlaybackState(state) {
+          if (!!this.setPlaybackStateCallback_)
+            this.setPlaybackStateCallback_(state);
+        }
+
+        setPlaybackStateCallback(callback) {
+          this.setPlaybackStateCallback_ = callback;
+        }
+
         enableAction(action) {
           if (!!this.enableDisableActionCallback_)
             this.enableDisableActionCallback_(action, true);
         }
 
         disableAction(action) {
           if (!!this.enableDisableActionCallback_)
             this.enableDisableActionCallback_(action, false);
         }
 
@@ skipping 11 matching lines @@
           this.clientCallback_ = callback;
         }
 
         getClient() {
           return this.client_;
         }
       }
 
       return new MediaSessionServiceMock(mojo.frameInterfaces);
     });