[tools/perf] Fix JavaScript interpolation in action_runner calls

tools/perf/page_sets/top_7_stress.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.
 from telemetry.page import page as page_module
 from telemetry.page import shared_page_state
 from telemetry import story
 
 
 def _GetCurrentLocation(action_runner):
   return action_runner.EvaluateJavaScript('document.location.href')
 
 
 def _WaitForLocationChange(action_runner, old_href):
-  # TODO(catapult:#3028): Fix interpolation of JavaScript values.
   action_runner.WaitForJavaScriptCondition(
-      'document.location.href != "%s"' % old_href)
+      'document.location.href != {{ old_href }}', old_href=old_href)
 
 
 class Top7StressPage(page_module.Page):
 
   def __init__(self, url, page_set, name=''):
     super(Top7StressPage, self).__init__(
         url=url, page_set=page_set, name=name,
         shared_page_state_class=shared_page_state.SharedDesktopPageState,
         credentials_path = 'data/credentials.json')
     self.archive_data_file = 'data/top_7_stress.json'
@@ skipping 289 matching lines @@
       archive_data_file='data/top_7_stress.json',
       cloud_storage_bucket=story.PARTNER_BUCKET)
 
     self.AddStory(GoogleWebSearchPage(self))
     self.AddStory(GmailPage(self))
     self.AddStory(GoogleCalendarPage(self))
     self.AddStory(GooglePlusPage(self))
     self.AddStory(BlogspotPage(self))
     self.AddStory(WordpressPage(self))
     self.AddStory(FacebookPage(self))