Enable material design media playback UI on all platforms.

third_party/WebKit/LayoutTests/media/controls-volume-slider.html

Index: third_party/WebKit/LayoutTests/media/controls-volume-slider.html
diff --git a/third_party/WebKit/LayoutTests/media/controls-volume-slider.html b/third_party/WebKit/LayoutTests/media/controls-volume-slider.html
index faec2a9a1b0d10c7643b19dec999606b0dcaebfd..3f5d61c3c327069759549d1bde65e2bc4440196f 100644
--- a/third_party/WebKit/LayoutTests/media/controls-volume-slider.html
+++ b/third_party/WebKit/LayoutTests/media/controls-volume-slider.html
@@ -20,6 +20,8 @@
                 var coords = mediaControlsButtonCoordinates(audio, "volume-slider");
                 eventSender.mouseMoveTo(coords[0], coords[1]);
                 eventSender.mouseDown();
+                eventSender.mouseMoveTo(coords[0]-1, coords[1]);
+                eventSender.mouseMoveTo(coords[0], coords[1]);
                 eventSender.mouseUp();
 
                 testExpected("audio.volume", 0.4, '>');