Files.app Test: check the cast icon in drive volume

ui/file_manager/video_player/js/background.js

Index: ui/file_manager/video_player/js/background.js
diff --git a/ui/file_manager/video_player/js/background.js b/ui/file_manager/video_player/js/background.js
index ced6cb3aa44b5626af5877c40bb90e56afe8ea37..8925b40e4c682e2a2838305be91a3b2299bf367b 100644
--- a/ui/file_manager/video_player/js/background.js
+++ b/ui/file_manager/video_player/js/background.js
@@ -84,8 +84,13 @@ function open(videos) {
     // Stores the window for test purpose.
     appWindowsForTest[videos[0].entry.name] = createdWindow;
 
-    createdWindow.setIcon('images/icon/video-player-64.png');
     createdWindow.contentWindow.videos = videos;
+    createdWindow.setIcon('images/icon/video-player-64.png');
+
+    if (chrome.test) {
+      createdWindow.contentWindow.loadMockCastExtensionForTest = true;
+    }
+
     chrome.runtime.sendMessage({ready: true}, function() {});
   }).catch(function(error) {
     console.error('Launch failed', error.stack || error);