Added integration tests for falling back from the HTTP proxy to direct.

tools/chrome_proxy/integration_tests/chrome_proxy_measurements.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 base64
 import logging
 import urlparse
 
 from integration_tests import chrome_proxy_metrics as metrics
 from metrics import loading
@@ skipping 242 matching lines @@
 
   def CustomizeBrowserOptions(self, options):
     super(ChromeProxyClientVersion,
           self).CustomizeBrowserOptions(options)
     options.AppendExtraBrowserArgs('--user-agent="Chrome/32.0.1700.99"')
 
   def AddResults(self, tab, results):
     self._metrics.AddResultsForClientVersion(tab, results)
 
 
+class ChromeProxyHTTPToDirectFallback(ChromeProxyValidation):
+  """Correctness measurement for HTTP proxy fallback to direct."""
+
+  def __init__(self):
+    super(ChromeProxyHTTPToDirectFallback, self).__init__(
+        restart_after_each_page=True)
+
+  def WillNavigateToPage(self, page, tab):
+    super(ChromeProxyHTTPToDirectFallback, self).WillNavigateToPage(page, tab)
+    # In order to have this test run starting from the HTTP fallback proxy,
+    # the startup URL is set such that it will trigger a proxy fallback.
+    # Verify that this is true before beginning the test proper.
+    proxies = [
+        self._metrics.effective_proxies['proxy'],
+        self._metrics.effective_proxies['fallback'],
+        self._metrics.effective_proxies['direct']]
+    bad_proxies = [self._metrics.effective_proxies['proxy']]
+    self._metrics.VerifyProxyInfo(tab, proxies, bad_proxies)
+
+  def AddResults(self, tab, results):
+    self._metrics.AddResultsForHTTPToDirectFallback(tab, results)
+
+
 class ChromeProxySmoke(ChromeProxyValidation):
   """Smoke measurement for basic chrome proxy correctness."""
 
   def __init__(self):
     super(ChromeProxySmoke, self).__init__()
 
   def WillNavigateToPage(self, page, tab):
     super(ChromeProxySmoke, self).WillNavigateToPage(page, tab)
     if page.name == 'safebrowsing':
       self._expect_timeout = True
@@ skipping 16 matching lines @@
             ],
         'bypass': [self._metrics.AddResultsForBypass],
         'safebrowsing': [self._metrics.AddResultsForSafebrowsing],
         }
     if not self._page.name in page_to_metrics:
       raise page_test.MeasurementFailure(
           'Invalid page name (%s) in smoke. Page name must be one of:\n%s' % (
           self._page.name, page_to_metrics.keys()))
     for add_result in page_to_metrics[self._page.name]:
       add_result(tab, results)