Add Histogram functionality.

tools/chrome_proxy/webdriver/simple_smoke.py

 # Copyright 2016 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 time
 
 from common import IntegrationTest
 from common import TestDriver
 
 
 class SimpleSmoke(IntegrationTest):
 
   # Simple example integration test.
   def TestCheckPageWithProxy(self):
     with TestDriver() as t:
       t.AddChromeArgs(['--enable-spdy-proxy-auth'])
       t.SetURL('http://check.googlezip.net/test.html')
       t.LoadPage()
       print 'Document Title: ', t.ExecuteJavascriptStatement('document.title',
         timeout=1)
       time.sleep(5)
       responses = t.GetHTTPResponses()
       for response in responses:
         print "URL: %s, ViaHeader: %s, XHR: %s" % (response.url,
           response.ResponseHasViaHeader(), response.WasXHR())
 
+  # Show how to get a histogram.
+  def TestPingbackHistogram(self):
+    with TestDriver() as t:
+      t.AddChromeArgs(['--enable-spdy-proxy-auth'])

[RyanSturm, 2016/12/07 20:20:44]

nit:
s/AddChromeArgs(['--enable-spdy-proxy-auth'])/AddChromeArg('--enable-spdy-proxy-auth')/

[Robert Ogden, 2016/12/07 21:11:53]

Done.

+      t.SetURL('http://check.googlezip.net/test.html')
+      t.LoadPage()
+      t.LoadPage()
+      print t.GetHistogram('DataReductionProxy.Pingback.Attempted')
+
 if __name__ == '__main__':
   test = SimpleSmoke()
   test.RunAllTests()