Add Wait* API to ActionRunner to wrap over WaitAction.

tools/perf/page_sets/browser_control_click.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 BrowserControlClickPage(page_module.Page):
 
   """ Why: Use a JavaScript .click() call to attach and detach a DOM tree
   from a basic document.
   """
 
   def __init__(self, page_set):
     super(BrowserControlClickPage, self).__init__(
       url='file://endure/browser_control_click.html',
       page_set=page_set,
      name='browser_control_click')
     self.user_agent_type = 'desktop'
 
   def RunNavigateSteps(self, action_runner):
     action_runner.NavigateToPage(self)
-    action_runner.RunAction(WaitAction(
-      {
-        'xpath': 'id("attach")',
-        'condition': 'element'
-      }))
+    action_runner.WaitForElement('#attach')
 
   def RunEndure(self, action_runner):
     action_runner.RunAction(ClickElementAction(
       {
         'xpath': 'id("attach")'
       }))
-    action_runner.RunAction(WaitAction(
-      {
-        'seconds': 0.5
-      }))
+    action_runner.Wait(0.5)
     action_runner.RunAction(ClickElementAction(
       {
         'xpath': 'id("detach")'
       }))
-    action_runner.RunAction(WaitAction(
-      {
-        'seconds': 0.5
-      }))
+    action_runner.Wait(0.5)
 
 
 class BrowserControlClickPageSet(page_set_module.PageSet):
 
   """ Chrome Endure control test for the browser. """
 
   def __init__(self):
     super(BrowserControlClickPageSet, self).__init__(
       user_agent_type='desktop')
 
     self.AddPage(BrowserControlClickPage(self))