Media Remoting: Add interstitial elements to media element shadow dom.

third_party/WebKit/public/blink_image_resources.grd

Index: third_party/WebKit/public/blink_image_resources.grd
diff --git a/third_party/WebKit/public/blink_image_resources.grd b/third_party/WebKit/public/blink_image_resources.grd
index adcb7f4f33f4716e89ae90449f707514b4dfee59..16f657436423731b86760a6c242e422d0e1ecb85 100644
--- a/third_party/WebKit/public/blink_image_resources.grd
+++ b/third_party/WebKit/public/blink_image_resources.grd
@@ -25,6 +25,8 @@
       <structure type="chrome_scaled_image" name="IDR_MEDIAPLAYER_OVERLAY_CAST_BUTTON_OFF" file="blink/mediaplayer_overlay_cast_off.png" />
       <structure type="chrome_scaled_image" name="IDR_MEDIAPLAYER_OVERLAY_CAST_BUTTON_ON" file="blink/mediaplayer_overlay_cast_on.png" />
       <structure type="chrome_scaled_image" name="IDR_MEDIAPLAYER_OVERLAY_PLAY_BUTTON" file="blink/mediaplayer_overlay_play.png" />
+      <structure type="chrome_scaled_image" name="IDR_MEDIA_REMOTING_CAST_ICON"
+      file="blink/mediaremoting_cast.png" />
       <structure type="chrome_scaled_image" name="IDR_MEDIAPLAYER_TRACKSELECTION_CHECKMARK" file="blink/mediaplayer_trackselection_checkmark.png" />
       <structure type="chrome_scaled_image" name="IDR_MEDIAPLAYER_CLOSEDCAPTIONS_ICON" file="blink/mediaplayer_closedcaptions_icon.png" />
       <structure type="chrome_scaled_image" name="IDR_MEDIAPLAYER_OVERFLOW_MENU_ICON" file="blink/mediaplayer_overflow_menu.png" />