video_YouTubeHTML5 often failed on daisy
other boards are good.

  File "/usr/local/autotest/tests/video_YouTubeHTML5/video_YouTubeHTML5.py", line 72, in run_once
    self.run_youtube_tests(cr.browser)
  File "/usr/local/autotest/tests/video_YouTubeHTML5/video_YouTubeHTML5.py", line 49, in run_youtube_tests
    yh.wait_for_player_state(PLAYER_PLAYING_STATE)
  File "/usr/local/autotest/cros/video/youtube_helper.py", line 94, in wait_for_player_state
    sleep_interval=1)
  File "/usr/local/autotest/common_lib/utils.py", line 2752, in poll_for_condition
    raise exception
TestError: Video failed to load. Player expected status: Playing and current status: Unstarted.