Fixed test for height of player when CC is disabled.

It turned out that we were reading the heights of the contols and other elements
before we initialized the heights.

common/lib/xmodule/xmodule/js/spec/videoalpha/video_caption_spec.js

 (function() {
-  xdescribe('VideoCaptionAlpha', function() {
+  describe('VideoCaptionAlpha', function() {
     var state, videoPlayer, videoCaption, videoSpeedControl, oldOTBD;
 
     function initialize() {
@@ -369,14 +369,21 @@
         });
 
         it('when CC button is disabled ', function() {
-          var realHeight = parseInt($('.subtitles').css('maxHeight'), 10),
-              videoWrapperHeight = $('.video-wrapper').height(),
-              progressSliderHeight = videoControl.sliderEl.height(),
-              shouldBeHeight = videoWrapperHeight - 0.5 * progressSliderHeight;
+          var realHeight, videoWrapperHeight, progressSliderHeight,
+            controlHeight, shouldBeHeight;
 
           state.captionsHidden = true;
           videoCaption.setSubtitlesHeight();
-          expect(realHeight).toBeCloseTo(shouldBeHeight, 2);
+
+          realHeight = parseInt($('.subtitles').css('maxHeight'), 10);
+          videoWrapperHeight = $('.video-wrapper').height();
+          progressSliderHeight = videoControl.sliderEl.height();
+          controlHeight = videoControl.el.height();
+          shouldBeHeight = videoWrapperHeight -
+                           0.5 * progressSliderHeight -
+                           controlHeight;
+
+          expect(realHeight).toBe(shouldBeHeight);
         });
       });