[Presentation API] 1-UA presentation support + presenter APIs.

extensions/renderer/resources/media_router_bindings.js

Index: extensions/renderer/resources/media_router_bindings.js
diff --git a/extensions/renderer/resources/media_router_bindings.js b/extensions/renderer/resources/media_router_bindings.js
index 86ea2173273d3493db74a10456731a3f580ef5a0..67b0503f870f383736d8582ca21f46dac6c9051a 100644
--- a/extensions/renderer/resources/media_router_bindings.js
+++ b/extensions/renderer/resources/media_router_bindings.js
@@ -78,7 +78,8 @@ define('media_router_bindings', [
       // Begin newly added properties, followed by the milestone they were
       // added.  The guard should be safe to remove N+2 milestones later.
       'for_display': route.forDisplay, // M47
-      'off_the_record': !!route.offTheRecord  // M50
+      'off_the_record': !!route.offTheRecord,  // M50
+      'is_offscreen_presentation': route.isOffscreenPresentation || false // M53
     });
   }