[Telemetry refactor] Migrate clients to new JavaScript API (batch 3)

tools/chrome_proxy/integration_tests/chrome_proxy_pagesets/pass_through.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 common.chrome_proxy_shared_page_state import ChromeProxySharedPageState
 from telemetry.page import page as page_module
 from telemetry import story
 
 class PassThroughPage(page_module.Page):
   """
   A test page for the chrome proxy pass-through tests.
   """
 
   def __init__(self, url, page_set):
     super(PassThroughPage, self).__init__(url=url, page_set=page_set,
         shared_page_state_class=ChromeProxySharedPageState)
 
   def RunNavigateSteps(self, action_runner):
     super(PassThroughPage, self).RunNavigateSteps(action_runner)
-    action_runner.ExecuteJavaScript('''
+    action_runner.ExecuteJavaScript2('''
         (function() {
           var request = new XMLHttpRequest();
-          request.open("GET", "%s");
+          request.open("GET", {{ url }});
           request.setRequestHeader("Chrome-Proxy-Accept-Transform", "identity");
           request.send(null);
-        })();''' % (self.url))
+        })();''', url=self.url)
     action_runner.Wait(1)
 
 
 class PassThroughStorySet(story.StorySet):
   """ Chrome proxy test sites """
 
   def __init__(self):
     super(PassThroughStorySet, self).__init__()
 
     urls_list = [
       'http://check.googlezip.net/image.png',
     ]
 
     for url in urls_list:
       self.AddStory(PassThroughPage(url, self))