Added integration test to Chrome Proxy to verify direct connection on remote site timeout

tools/chrome_proxy/integration_tests/chrome_proxy_metrics.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 logging
 import os
 import time
 
 from common import chrome_proxy_metrics
 from common import network_metrics
@@ skipping 854 matching lines @@
           'Expected 1 pingback success and no failures, but '
           'there were %d succesful pingbacks and %d failed pingback attempts'
           % (succeeded, count - succeeded))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'attempted', 'count', attempted))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'succeeded_count', 'count', count))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'succeeded_sum', 'count', succeeded))
 
+  def AddResultsForClientBypassOnTimeout(self, tab, results):
+    bypass_count = 0
+    tab.WaitForDocumentReadyStateToBeComplete(timeout=30)
+    for resp in self.IterResponses(tab):
+      if resp.HasChromeProxyViaHeader():
+        r = resp.response
+        raise ChromeProxyMetricException, (
+            'Response for %s should not have via header after proxy timeout.\n'
+            'Reponse: status=(%d, %s)\nHeaders:\n %s' % (
+                r.url, r.status, r.status_text, r.headers))
+      else:
+        bypass_count += 1
+    if bypass_count == 0:
+      raise ChromeProxyMetricException('No pages were tested!')
+    results.AddValue(scalar.ScalarValue(
+        results.current_page, 'bypass', 'count', bypass_count))
+
 PROXIED = 'proxied'
 DIRECT = 'direct'
 
 
 class ChromeProxyVideoMetric(network_metrics.NetworkMetric):
   """Metrics for video pages.
 
   Wraps the video metrics produced by videowrapper.js, such as the video
   duration and size in pixels. Also checks a few basic HTTP response headers
   such as Content-Type and Content-Length in the video responses.
@@ skipping 112 matching lines @@
     except KeyError:
       raise ChromeProxyMetricException, 'No metrics found'
 
 # Returns whether |url| is a block-once test URL. Data Reduction Proxy has been
 # configured to always return block-once for these URLs.
 def IsTestUrlForBlockOnce(url):
   return (url == 'http://check.googlezip.net/blocksingle/' or
       url == ('http://chromeproxy-test.appspot.com/default?respBody=T0s='
               '&respHeader=eyJBY2Nlc3MtQ29udHJvbC1BbGxvdy1PcmlnaW4iOlsiKiJ'
               'dfQ==&respStatus=200&flywheelAction=block-once'))