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

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 common import chrome_proxy_measurements as measurements
 from common.chrome_proxy_measurements import ChromeProxyValidation
 from integration_tests import chrome_proxy_metrics as metrics
 from metrics import loading
 from telemetry.core import exceptions, util
 from telemetry.page import page_test
 

[sclittle, 2016/08/03 22:30:09]

Could you explain what the blackhole server does? Does it blackhole the initial
connection, or does it just blackhole after it receives the HTTP request headers
from the client?

+BLACKHOLE_SERVER_URL = 'http://blackhole-1470152441488.appspot.com'

[sclittle, 2016/08/03 22:30:09]

Where is the implementation of this? For simplicity, it might be better to
implement the server support as part of the chromeproxy testserver if possible:
https://cs.chromium.org/chromium/src/tools/chrome_proxy/testserver/ and the
external target is http://chromeproxy-test.appspot.com/

That way, the server implementation will be present in the open source codebase
here so that it can be modified easily by other people. Plus, it means that we
don't have to rely on an entirely different service to be up for the tests to
pass (meaning less flakiness), or worry about provisioning separately for this
service.

+
+class ChromeProxyClientBypassOnTimeout(ChromeProxyValidation):
+  """Tests that client bypasses proxy after proxy timeouts on HTTP

[sclittle, 2016/08/03 22:30:09]

nit: per Google Python style guide, the summary of the class comment or function
comment should all fit on one line.
https://google.github.io/styleguide/pyguide.html#Comments

[Robert Ogden, 2016/08/08 16:46:41]

Done.

+  response.
+  """
+
+  def __init__(self):
+    super(ChromeProxyClientBypassOnTimeout, self).__init__(
+        restart_after_each_page=True,
+        metrics=metrics.ChromeProxyMetric())
+
+  def CustomizeBrowserOptions(self, options):
+    super(ChromeProxyClientBypassOnTimeout, self).CustomizeBrowserOptions(
+        options)
+    self._is_chrome_proxy_enabled = False
+    options.AppendExtraBrowserArgs('--data-reduction-proxy-http-proxies='
+        + BLACKHOLE_SERVER_URL)
+
+  def AddResults(self, tab, results):
+    self._metrics.AddResultsForClientBypassOnTimeout(tab, results)
 
 class ChromeProxyDataSaving(page_test.PageTest):
   """Chrome proxy data saving measurement."""
   def __init__(self, *args, **kwargs):
     super(ChromeProxyDataSaving, self).__init__(*args, **kwargs)
     self._metrics = metrics.ChromeProxyMetric()
     self._enable_proxy = True
 
   def CustomizeBrowserOptions(self, options):
     if self._enable_proxy:
@@ skipping 644 matching lines @@
         metrics=metrics.ChromeProxyMetric())
 
   def CustomizeBrowserOptions(self, options):
     super(ChromeProxyPingback, self).CustomizeBrowserOptions(options)
     options.AppendExtraBrowserArgs(
       '--enable-data-reduction-proxy-force-pingback')
     options.AppendExtraBrowserArgs(
       '--enable-stats-collection-bindings')
 
   def AddResults(self, tab, results):
-    self._metrics.AddResultsForPingback(tab, results)
+    self._metrics.AddResultsForPingback(tab, results)

[sclittle, 2016/08/03 22:30:09]

tiny nit: do you know what's up with the newline added here at the end? I don't
think it's really a problem, but could you remove it if you added it
accidentally?

[Robert Ogden, 2016/08/08 16:46:41]

bustamante@ and I both checked this out, there's not a newline at the end here
when you view the file. Not sure what's up with the diff