Adding HTML5 track(caption) test case in PyAuto media functional tests.

chrome/test/functional/media/media_test_base.py

 #!/usr/bin/python
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """A framework to run PyAuto HTML media tests.
 
 This PyAuto powered script plays media (video or audio) files (using the HTML5
 tag embedded in an HTML file). The parameters needed to run this test are
 passed in the form of environment variables (such as the number of runs).
@@ skipping 63 matching lines @@
 
     tag = os.getenv(MediaTestEnvNames.MEDIA_TAG_ENV_NAME,
                     self.DEFAULT_MEDIA_TAG_NAME)
     query_dictionary = {'tag': tag, 'media': media_filename}
     # This parameter tricks the media cache into thinking
     # it's a new file every time.
     # However, it looks like does not make much difference in
     # performance.
     if os.getenv(MediaTestEnvNames.ADD_T_PARAMETER_ENV_NAME):
       query_dictionary['t'] = 'dummy'
+    track_file = os.getenv(MediaTestEnvNames.TRACK_FILE_ENV_NAME)
+    if track_file:
+      query_dictionary['track'] = track_file
     query_str = '&'.join(
         [k + '=' + str(v) for (k, v) in query_dictionary.items()])
     if player_html_url_nickname == self.DEFAULT_PLAYER_HTML_URL_NICKNAME:
       # Default is local file under DataDir().
       file_url = self.GetFileURLForDataPath(
           os.path.join('media', 'html', self.GetPlayerHTMLFileName()))
       url = file_url + '?' + query_str
     else:
       url = player_html_url + '?' + query_str
     parameter_str = '%s_%s_%s' % (
@@ skipping 104 matching lines @@
     """
     pass
 
   def GetPlayerHTMLFileName(self):
     """A method to get the player HTML file name."""
     return 'media_playback.html'
 
 
 if __name__ == '__main__':
   pyauto_media.Main()