Add Wait* API to ActionRunner to wrap over WaitAction.

tools/perf/page_sets/gmail_compose_discard.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.
+
+import re
+
 # 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
 
 
+def _CreateXpathFunction(xpath):
+  return ('document.evaluate(%s, document, null, '
+          'XPathResult.FIRST_ORDERED_NODE_TYPE, null)'
+          '.singleNodeEvaluate') % re.escape(xpath)
+
+
 class GmailComposeDiscardPage(page_module.Page):
 
   """ Why: Compose and discard a new email """
 
   def __init__(self, page_set):
     super(GmailComposeDiscardPage, self).__init__(
       url='https://mail.google.com/mail/',
       page_set=page_set)
     self.credentials_path = 'data/credentials.json'
     self.credentials = 'google'
     self.user_agent_type = 'desktop'
 
   def RunNavigateSteps(self, action_runner):
     action_runner.NavigateToPage(self)
-    action_runner.RunAction(WaitAction(
-      {
-        'javascript': (
-          'window.gmonkey !== undefined &&'
-          'document.getElementById("gb") !== null')
-      }))
+    action_runner.WaitForJavaScriptCondition(
+        'window.gmonkey !== undefined &&'
+        'document.getElementById("gb") !== null')
 
   def ComposeClick(self, action_runner):
     action_runner.ExecuteJavaScript('''
       var button=document.evaluate('//div[text()="COMPOSE"]',
           document,null,XPathResult.FIRST_ORDERED_NODE_TYPE,null)
           .singleNodeValue;
       var mousedownevent=new MouseEvent('mousedown',true,true,window,0,0,0,0,0,
         false,false,false,false,0,null);
       var mouseupevent=new MouseEvent('mouseup',true,true,window,0,0,0,0,0,
         false,false,false,false,0,null);
       button.dispatchEvent(mousedownevent);
       button.dispatchEvent(mouseupevent);''')
 
   def RunEndure(self, action_runner):
-    action_runner.RunAction(WaitAction(
-      {
-        'xpath': '//div[text()="COMPOSE"]',
-        'condition': 'element'
-      }))
+    action_runner.WaitForElement(
+        element_function=_CreateXpathFunction('//div[text()="COMPOSE"]'))
     self.ComposeClick(action_runner)
-    action_runner.RunAction(WaitAction({"seconds": 1}))
-    action_runner.RunAction(WaitAction(
-      {
-        'condition': 'element',
-        'selector': 'div[class~="oh"][data-tooltip="Discard draft"]'
-      }))
+    action_runner.Wait(1)
+    action_runner.WaitForElement(
+        'div[class~="oh"][data-tooltip="Discard draft"]')
     action_runner.RunAction(ClickElementAction(
       {
         'selector': 'div[class~="oh"][data-tooltip="Discard draft"]'
       }))
-    action_runner.RunAction(WaitAction({'seconds': 1}))
+    action_runner.Wait(1)
 
 
 class GmailComposeDiscardPageSet(page_set_module.PageSet):
 
   """
   Description: Gmail endure test: compose and discard an email.
   """
 
   def __init__(self):
     super(GmailComposeDiscardPageSet, self).__init__(
       credentials_path='data/credentials.json',
       user_agent_type='desktop')
 
     self.AddPage(GmailComposeDiscardPage(self))