Support to repeat one song in Audio Player.

ui/file_manager/audio_player/elements/control_panel.css

Index: ui/file_manager/audio_player/elements/control_panel.css
diff --git a/ui/file_manager/audio_player/elements/control_panel.css b/ui/file_manager/audio_player/elements/control_panel.css
index a538297a0f31ae2803b044e02249edc9f7bdfbb7..e85e72918309e27a60746061feaff1bfdb41b404 100644
--- a/ui/file_manager/audio_player/elements/control_panel.css
+++ b/ui/file_manager/audio_player/elements/control_panel.css
@@ -141,18 +141,11 @@ paper-slider.disabled {
   pointer-events: auto;
 }
 
-.media-button.repeat {
+.media-button.repeat-mode {
   margin-left: 8px;
   margin-right: 0;
 }
 
-.media-button.repeat {
-  background-image: -webkit-image-set(
-      url(../assets/100/player_button_repeat.png) 1x,
-      url(../assets/200/player_button_repeat.png) 2x);
-  pointer-events: auto;
-}
-
 .media-button.play {
   margin-left: 4px;
   margin-right: 4px;