[Telemetry refactor] Drop "2" from method calls to JS API

tools/perf/page_sets/tough_image_decode_cases.py

 # Copyright 2015 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.
 from telemetry.page import page as page_module
 from telemetry.page import shared_page_state
 from telemetry import story
 
 class ToughImageDecodeCasesPage(page_module.Page):
 
   def __init__(self, url, name, page_set):
     super(ToughImageDecodeCasesPage, self).__init__(
       url=url,
       page_set=page_set,
       name=name,
       shared_page_state_class=shared_page_state.SharedMobilePageState)
     self.archive_data_file = 'data/tough_image_decode_cases.json'
 
   def RunPageInteractions(self, action_runner):
-    action_runner.WaitForJavaScriptCondition2(
+    action_runner.WaitForJavaScriptCondition(
       'document.readyState === "complete"')
     action_runner.ScrollPage(direction='down', speed_in_pixels_per_second=5000)
     with action_runner.CreateGestureInteraction('ScrollAction'):
       action_runner.ScrollPage(direction='up', speed_in_pixels_per_second=5000)
 
 class ToughImageDecodeCasesPageSet(story.StorySet):
 
   """
   Description: A collection of difficult image decode tests
   """
 
   def __init__(self):
     super(ToughImageDecodeCasesPageSet, self).__init__(
       archive_data_file='data/tough_image_decode_cases.json',
       cloud_storage_bucket=story.PUBLIC_BUCKET)
 
     page_name_list = [
       'http://localhost:9000/cats-unscaled.html',
       'http://localhost:9000/cats-viewport-width.html'
     ]
 
     for name in page_name_list:
       self.AddStory(ToughImageDecodeCasesPage(
         name, name, self))