Bug 1293601 - Show slider and mute button at first show on video touch control. r=jaws

MozReview-Commit-ID: E9cilyGDZRK

--HG--
extra : transplant_source : %1A%D0%AA%FC%BEl%20%CB%0E%0F%8F9%20%16%AFk8%01%C4%B7

mobile/android/themes/core/touchcontrols.css

@@ -217,9 +217,6 @@
 }
 
 .volumeStack,
-.controlBar[firstshow="true"] .muteButton,
-.controlBar[firstshow="true"] .scrubberStack,
-.controlBar[firstshow="true"] .durationBox,
 .timeLabel {
   display: none;
 }