Add Wait* API to ActionRunner to wrap over WaitAction.

tools/perf/page_sets/media_cns_cases.py

 # Copyright 2014 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.
 # pylint: disable=W0401,W0614
 from telemetry.page.actions.all_page_actions import *
 from telemetry.page import page as page_module
 from telemetry.page import page_set as page_set_module
 
 
 class BasicPlayPage(page_module.Page):
@@ skipping 12 matching lines @@
   def RunMediaMetrics(self, action_runner):
     self.PlayAction(action_runner)
 
   def SeekBeforeAndAfterPlayhead(self, action_runner):
     action_runner.RunAction(PlayAction(
       {
         'wait_for_playing': True,
         'wait_for_ended': False
       }))
     # Wait for 1 second so that we know the play-head is at ~1s.
-    action_runner.RunAction(WaitAction(
-      {
-        'seconds': 1
-      }))
+    action_runner.Wait(1)
     # Seek to before the play-head location.
     action_runner.RunAction(SeekAction(
       {
         'seek_time': '0.5',
         'wait_for_seeked': True,
         'seek_label': 'seek_warm'
       }))
     # Seek to after the play-head location.
     action_runner.RunAction(SeekAction(
       {
@@ skipping 80 matching lines @@
       # pylint: disable=C0301
       'file://tough_video_cases/video.html?id=wifi_mp4&src=tulip2.mp4&type=audio&net=wifi',
       # pylint: disable=C0301
       'file://tough_video_cases/video.html?id=wifi_ogv&src=tulip2.ogv&type=audio&net=wifi',
       # pylint: disable=C0301
       'file://tough_video_cases/video.html?id=wifi_webm&src=tulip2.webm&type=audio&net=wifi'
     ]
 
     for url in urls_list2:
       self.AddPage(SeekBeforeAndAfterPlayheadPage(url, self))