[Media Router] Replace route messaging API.

chrome/browser/media/router/mojo/media_router.mojom

 // 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.
 
 module media_router.interfaces;
 
 // Represents an output sink to which media can be routed.
 struct MediaSink {
   enum IconType {
     CAST,
@@ skipping 188 matching lines @@
   // route given by |route_id|.
   //
   // The presentation ID of the new route will be |presentation_id|, but it may
   // be overridden by a provider implementation.  The presentation ID will be
   // used by the presentation API to refer to the created route.
   //
   // |origin| and |tab_id| are used for validating same-origin/tab scopes; see
   // CreateRoute for additional documentation.
   //
   // If |timeout_millis| is positive, it will be used in place of the default
-  // timeout defined by Media Route Provider Manager; see CreateRoute for additional
-  // documentation.
+  // timeout defined by Media Route Provider Manager; see CreateRoute for
+  // additional documentation.
   //
   // If the route request was created by an off the record (incognito) profile,
   // |off_the_record| must be true.
   //
   // If the operation was successful, |route| will be defined and
   // |error_text| will be null. If the operation failed, |route| will be null
   // and |error_text| will be set.
   //
   // |result| will be set to OK if successful, or an error code if an error
   // occurred.
@@ skipping 44 matching lines @@
   // Stops querying the state of all media routes in the context of
   // the |media_source|.  StartObservingMediaRoutes() has
   // to be called with the same |media_source| for this to have any effect even
   // if it's empty.  Thus, StartObservingMediaRoutes(media_source) must be
   // matched with StopObservingMediaRoutes(media_source).
   // Calling StopObservingMediaRoutes() without a media_source will stop
   // any media routes queries associated with emtpy strings (queries
   // that being with StartObservingMediaRoutes()).
   StopObservingMediaRoutes(string media_source);
 
-  // Called when the MediaRouter is ready to get the next batch of messages
-  // associated with |route_id|.
-  // |messages| returned will contain the batch of messages.
-  // |messages| will be empty if |StopListeningForRouteMessages| was invoked.
-  // |error| indicates if a permanent error occurred. If true, then subsequent
-  // calls will also return with |error| being true.
-  ListenForRouteMessages(string route_id) =>
-      (array<RouteMessage> messages, bool error);
+  // Starts listening for messages from the media sink for the route given by
+  // |route_id|.
+  // |MediaRouter::OnRouteMessagesReceived| will be invoked when a batch of
+  // messages arrives, or when there is an error.
+  // |StopListeningForRouteMessages| will stop the Media Router from receiving
+  // further messages for |route_id|.
+  StartListeningForRouteMessages(string route_id);
 
   // Called when there are no more listeners for messages for |route_id|.
-  // Calling this will resolve the pending |ListenForRouteMessages| callback
-  // with an empty list.
   StopListeningForRouteMessages(string route_id);
 
   // Indicates that a PresentationConnection that was connected to route
   // |route_id| has been closed (via .close(), garbage collection or
   // navigation).
   DetachRoute(string route_id);
 
   // Enables mDNS discovery. No-op if mDNS discovery is already enabled.
   // Calling this will trigger a firewall prompt on Windows if there is not
   // already a firewall rule for mDNS.
@@ skipping 70 matching lines @@
 
   // Called when the state of presentation connected to route |route_id| has
   // changed to |state|.
   OnPresentationConnectionStateChanged(
       string route_id, PresentationConnectionState state);
 
   // Called when the presentation connected to route |route_id| has closed.
   OnPresentationConnectionClosed(
       string route_id, PresentationConnectionCloseReason reason,
       string message);
+
+  // Called when the a batch of messages arrives from the media sink for the
+  // route given by |route_id|.
+  // |StartListeningForRouteMessages| must be called first in order to receive
+  // messages.
+  // |route_id|: ID of route of the messages.
+  // |messages|: A non-empty list of messages received.
+  OnRouteMessagesReceived(string route_id,
+                          array<RouteMessage> messages);
 };