[Media Router] Implement JoinRoute + update CreateRoute API.

chrome/browser/media/router/media_router.h

 // 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.
 
 #ifndef CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTER_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 11 matching lines @@
 
 // Type of callback used in |CreateRoute()|. Callback is invoked when the
 // route request either succeeded or failed.
 // The first argument is the route created. If the route request failed, this
 // will be a nullptr.
 // The second argument is the error string, which will be nonempty if the route
 // request failed.
 using MediaRouteResponseCallback =
     base::Callback<void(scoped_ptr<MediaRoute>, const std::string&)>;
 
+// Used in cases where a tab ID is not applicable in CreateRoute/JoinRoute.
+const int kInvalidTabId = -1;
+
 // An interface for handling resources related to media routing.
 // Responsible for registering observers for receiving sink availability
 // updates, handling route requests/responses, and operating on routes (e.g.
 // posting messages or closing).
 class MediaRouter {
  public:
   using SendRouteMessageCallback = base::Callback<void(bool sent)>;
 
   virtual ~MediaRouter() {}
 
   // Creates a media route from |source_id| to |sink_id|.
+  // |origin| is the URL of requestor's page.
+  // |tab_id| is the ID of the tab in which the request was made.
+  // |origin| and |tab_id| are used for enforcing same-origin and/or same-tab
+  // scope for JoinRoute() requests. (e.g., if enforced, the page
+  // requesting JoinRoute() must have the same origin as the page that requested
+  // CreateRoute()).
+  // The caller may pass in|kInvalidTabId| if tab is not applicable.
   // |callback| is invoked with a response indicating success or failure.
   virtual void CreateRoute(const MediaSource::Id& source_id,
                            const MediaSink::Id& sink_id,
+                           const GURL& origin,
+                           int tab_id,
                            const MediaRouteResponseCallback& callback) = 0;
 
+  // Joins an existing route identified by |presentation_id|.
+  // |source|: The source to route to the existing route.
+  // |presentation_id|: Presentation ID of the existing route.
+  // |origin|, |tab_id|: Origin and tab of the join route request. Used for
+  // validation when enforcing same-origin and/or same-tab scope.
+  // (See CreateRoute documentation).
+  // |callback| is invoked with a response indicating success or failure.
+  virtual void JoinRoute(const MediaSource::Id& source,
+                         const std::string& presentation_id,
+                         const GURL& origin,
+                         int tab_id,
+                         const MediaRouteResponseCallback& callback) = 0;
+
   // Closes the media route specified by |route_id|.
   virtual void CloseRoute(const MediaRoute::Id& route_id) = 0;
 
   // Posts |message| to a MediaSink connected via MediaRoute with |route_id|.
   // TODO(imcheng): Support additional data types: Blob, ArrayBuffer,
   // ArrayBufferView.
   virtual void SendRouteMessage(const MediaRoute::Id& route_id,
                                 const std::string& message,
                                 const SendRouteMessageCallback& callback) = 0;
 
@@ skipping 51 matching lines @@
   // in undefined behavior.
   virtual void AddIssuesObserver(IssuesObserver* observer) = 0;
 
   // Removes the IssuesObserver |observer|.
   virtual void RemoveIssuesObserver(IssuesObserver* observer) = 0;
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTER_H_