Updated acceptance tests.

cms/djangoapps/contentstore/features/video.feature

@@ -56,3 +56,5 @@ Feature: CMS.Video Component
     Then Captions become visible
     And Hover over CC button
     Then Captions become visible
+    And Hover over volume button
+    Then Captions become visible

cms/djangoapps/contentstore/features/video.py

@@ -110,7 +110,7 @@ def the_youtube_video_is_shown(_step):
 
 
 @step('Make sure captions are (.+)$')
-def make_sure_captions_are_closed(_step, captions_state):
+def set_captions_visibility_state(_step, captions_state):
     if captions_state == 'closed':
         if world.css_visible('.subtitles'):
             world.browser.find_by_css('.hide-subtitles').click()
@@ -119,9 +119,12 @@ def make_sure_captions_are_closed(_step, captions_state):
             world.browser.find_by_css('.hide-subtitles').click()
 
 
-@step('Hover over CC button$')
-def hover_over_cc_button(_step):
-    world.browser.find_by_css('.hide-subtitles').mouse_over()
+@step('Hover over (.+) button$')
+def hover_over_button(_step, button):
+    if button.strip() == 'CC':
+        world.browser.find_by_css('.hide-subtitles').mouse_over()
+    else:
+        world.browser.find_by_css('.volume').mouse_over()
 
 
 @step('Captions become (.+)$')