Video Player: Show a checkmark on the currently playing device in cast menu

ui/file_manager/video_player/css/cast_menu.css

Index: ui/file_manager/video_player/css/cast_menu.css
diff --git a/ui/file_manager/video_player/css/cast_menu.css b/ui/file_manager/video_player/css/cast_menu.css
index 161fd525f85f7424445f12e280efe1d811cf5c10..b4f9e32491cac1f1971d0e5b58bd15703bc88e3c 100644
--- a/ui/file_manager/video_player/css/cast_menu.css
+++ b/ui/file_manager/video_player/css/cast_menu.css
@@ -16,12 +16,20 @@
 }
 
 .cast-menu > :not(hr) {
+  -webkit-padding-end: 14px;
+  -webkit-padding-start: 19px;
   background-color: #fff;
   font-size: 12px;
-  padding: 5px 10px; /* top&bottom, left&right */
+  padding-bottom: 5px;
+  padding-top: 5px;
   text-overflow: ellipsis;
 }
 
+.cast-menu > [checked]:not(hr) {
+  /* A checkmark has 19 px width. */
+  -webkit-padding-start: 0;
+}
+
 .cast-menu > :not(hr):hover {
   background-color: #eee;
 }