[Media Router] Implement JoinRoute + update CreateRoute API.

extensions/renderer/resources/media_router_bindings.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 var mediaRouterObserver;
 
 define('media_router_bindings', [
     'mojo/public/js/bindings',
     'mojo/public/js/core',
     'content/public/renderer/service_provider',
@@ skipping 261 matching lines @@
 
   /**
    * Object containing callbacks set by the provider manager.
    * TODO(mfoltz): Better named ProviderManagerDelegate?
    *
    * @constructor
    * @struct
    */
   function MediaRouterHandlers() {
     /**
-     * @type {function(!string, !string, !string=, !string=, !number=}
+     * @type {function(!string, !string, !string, !string, !number}
      */
     this.createRoute = null;
 
     /**
      * @type {function(!string, !string, !string, !number)}
      */
     this.joinRoute = null;
 
     /**
      * @type {function(string)}
@@ skipping 89 matching lines @@
    * Stops querying for sinks capable of displaying |sourceUrn|.
    * @param {!string} sourceUrn
    */
   MediaRouter.prototype.stopObservingMediaSinks =
       function(sourceUrn) {
     this.handlers_.stopObservingMediaSinks(sourceUrn);
   };
 
   /**
    * Requests that |sinkId| render the media referenced by |sourceUrn|. If the
-   * request is from the Presentation API, then opt_origin and opt_tabId will
+   * request is from the Presentation API, then origin and tabId will
    * be populated.
-   * @param {!string} sourceUrn The media source to render.
-   * @param {!string} sinkId The media sink ID.
-   * @param {!string=} opt_presentationId Presentation ID from the site
+   * @param {!string} sourceUrn Media source to render.
+   * @param {!string} sinkId Media sink ID.
+   * @param {!string} presentationId Presentation ID from the site
    *     requesting presentation. TODO(mfoltz): Remove.
-   * @param {!string=} opt_origin The origin of the site requesting
-   *     presentation.
-   * @param {!number=} opt_tabId ID of the tab that requested presentation.
+   * @param {!string} origin Origin of site requesting presentation.
+   * @param {!number} tabId ID of tab requesting presentation.
    * @return {!Promise.<!Object>} A Promise resolving to an object describing
-   *     the newly created media route.
+   *     the newly created media route, or rejecting with an error message on
+   *     failure.
    */
   MediaRouter.prototype.createRoute =
-      function(sourceUrn, sinkId, opt_presentationId, opt_origin, opt_tabId) {
+      function(sourceUrn, sinkId, presentationId, origin, tabId) {
     return this.handlers_.createRoute(
-        sourceUrn, sinkId, opt_presentationId, opt_origin, opt_tabId)
+        sourceUrn, sinkId, presentationId, origin, tabId)
         .then(function(route) {
           // Sink name is not used, so it is omitted here.
           return {route: routeToMojo_(route, "")};
         }.bind(this))
         .catch(function(err) {
-          return {error_text: err.message};
+          return {error_text: 'Error creating route: ' + err.message};
         });
   };
 
   /**
    * Handles a request via the Presentation API to join an existing route given
-   * by |sourceUrn| and |presentationId|. |origin| and |tabId| are used so the
-   * media route provider can limit the scope by origin or tab.
-   * @param {!string} sourceUrn The media source to render.
-   * @param {!string} presentationId The presentation ID to join.
-   * @param {!string} origin The origin of the site requesting join.
-   * @param {!number} tabId The ID of the tab requesting join.
-   * @return {!Promise.<!Object>} Resolved with the route on success,
-   * or with an error message on failure.
+   * by |sourceUrn| and |presentationId|. |origin| and |tabId| are used for
+   * validating same-origin/tab scope.
+   * @param {!string} sourceUrn Media source to render.
+   * @param {!string} presentationId Presentation ID to join.
+   * @param {!string} origin Origin of site requesting join.
+   * @param {!number} tabId ID of tab requesting join.
+   * @return {!Promise.<!Object>} A Promise resolving to an object describing
+   *     the newly created media route, or rejecting with an error message on
+   *     failure.
    */
   MediaRouter.prototype.joinRoute =
       function(sourceUrn, presentationId, origin, tabId) {
     return this.handlers_.joinRoute(sourceUrn, presentationId, origin, tabId)
         .then(function(newRoute) {
           return {route: routeToMojo_(newRoute)};
         },
         function(err) {
           return {error_text: 'Error joining route: ' + err.message};
         });
@@ skipping 41 matching lines @@
   };
 
   mediaRouterObserver = new MediaRouterObserver(connector.bindHandleToProxy(
       serviceProvider.connectToService(
           mediaRouterMojom.MediaRouterObserver.name),
       mediaRouterMojom.MediaRouterObserver));
 
   return mediaRouterObserver;
 });