[polymer] Merge of master into polymer10-migration

telemetry/telemetry/internal/actions/media_action.py

 # Copyright 2013 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.
 
 """Common media action functions."""
 
 import logging
-import os
 
 from telemetry.core import util
 from telemetry.internal.actions import page_action
+from telemetry.internal.actions import utils
 
 
 class MediaAction(page_action.PageAction):
   def WillRunAction(self, tab):
     """Loads the common media action JS code prior to running the action."""
-    self.LoadJS(tab, 'media_action.js')
+    utils.InjectJavaScript(tab, 'media_action.js')
 
   def RunAction(self, tab):
     super(MediaAction, self).RunAction(tab)
 
-  def LoadJS(self, tab, js_file_name):
-    """Loads and executes a JS file in the tab."""
-    with open(os.path.join(os.path.dirname(__file__), js_file_name)) as f:
-      js = f.read()
-      tab.ExecuteJavaScript(js)
-
   def WaitForEvent(self, tab, selector, event_name, timeout_in_seconds):
     """Halts media action until the selector's event is fired.
 
     Args:
       tab: The tab to check for event on.
       selector: Media element selector.
       event_name: Name of the event to check if fired or not.
       timeout_in_seconds: Timeout to check for event, throws an exception if
           not fired.
     """
     util.WaitFor(lambda:
                      self.HasEventCompletedOrError(tab, selector, event_name),
                  timeout=timeout_in_seconds)
 
   def HasEventCompletedOrError(self, tab, selector, event_name):
     if tab.EvaluateJavaScript(
         'window.__hasEventCompleted("%s", "%s");' % (selector, event_name)):
       return True
     error = tab.EvaluateJavaScript('window.__error')
     if error:
       logging.error('Detected media error while waiting for %s: %s', event_name,
                     error)
       return True
     return False