[Presentation API] (alternative) 1-UA: send message between controller and receiver page

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.mojom;
 
 import "mojo/common/common_custom_types.mojom";
 
 // Represents an output sink to which media can be routed.
 struct MediaSink {
@@ skipping 32 matching lines @@
   // Specifies that the route is requested locally.
   bool is_local;
   // An optional path to an HTML page bundled bundled with the media router
   // component extension. When set, the route can have custom route detail as
   // well as its own route controls in the media router dialog.
   string? custom_controller_path;
   // Set to true if this route should be displayed for |media_sink_id| in UI.
   bool for_display;
   // Set to true if this route was created by an incognito profile.
   bool incognito;
+  // Set to true if this route corresponds to an offscreen presentation.
+  bool is_offscreen_presentation;
 };
 
 // Notifications or an actionable events to be shown to the user.
 // When is_blocking is true, media router UI shows issue only:
 //
 //       Title
 //       Message
 //       default_action_button secondary_action_button
 //
 // When is_blocking is false, media router UI uses banner:
@@ skipping 322 matching lines @@
 
   // 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);
 };