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

tools/chrome_proxy/integration_tests/chrome_proxy_measurements.py

Index: tools/chrome_proxy/integration_tests/chrome_proxy_measurements.py
diff --git a/tools/chrome_proxy/integration_tests/chrome_proxy_measurements.py b/tools/chrome_proxy/integration_tests/chrome_proxy_measurements.py
index 7c05b9517ef276252dfb6421111ff10ac04a47e0..81768fa5b62ad133de0648d3ec5340f977004aae 100644
--- a/tools/chrome_proxy/integration_tests/chrome_proxy_measurements.py
+++ b/tools/chrome_proxy/integration_tests/chrome_proxy_measurements.py
@@ -13,6 +13,28 @@ from metrics import loading
 from telemetry.core import exceptions, util
 from telemetry.page import page_test
 
+BLACKHOLE_SERVER = 'blackhole-1470152441488.appspot.com'

[bustamante, 2016/08/03 19:04:39]

I think you can combine these into BLACKHOLE_SERVER_URL, since the server itself
isn't used anywhere.

[Robert Ogden, 2016/08/03 21:12:32]

Done.

+BLACKHOLE_SERVER_DEFAULT_URL = 'http://' + BLACKHOLE_SERVER + ''
+
+class ChromeProxyClientBypassOnTimeout(ChromeProxyValidation):
+  """Tests that client bypasses proxy after proxy timeouts on HTTP
+  response

[bustamante, 2016/08/03 19:04:39]

Needs an ending period.

[Robert Ogden, 2016/08/03 21:12:32]

Done.

+  """
+
+  def __init__(self):
+    super(ChromeProxyClientBypassOnTimeout, self).__init__(
+        restart_after_each_page=True,
+        metrics=metrics.ChromeProxyMetric())
+    self._is_chrome_proxy_enabled = False
+
+  def CustomizeBrowserOptions(self, options):
+    if not self._is_chrome_proxy_enabled:

[bustamante, 2016/08/03 19:04:39]

This if statement isn't needed I don't think, since we'll always want to use the
flags below for this test.

Some cases will disable flywheel as part of the test, and the bit is used in
shared methods so only valid the response headers when we think flywheel is
enabled.  Or in specific tests that disable it.

[Robert Ogden, 2016/08/03 21:12:32]

Done.

+      options.AppendExtraBrowserArgs('--enable-spdy-proxy-auth')

[bustamante, 2016/08/03 19:04:39]

It's probably worth just calling the super ChromeProxyValidation, which will add
the --enable-spdy-proxy-auth and disable quic args (there was a quic experiment
that would occasionally break our tests).

[Robert Ogden, 2016/08/03 21:12:32]

Done.

+      options.AppendExtraBrowserArgs('--data-reduction-proxy-http-proxies='
+          + BLACKHOLE_SERVER_DEFAULT_URL)
+
+  def AddResults(self, tab, results):
+    self._metrics.AddResultsForClientBypassOnTimeout(tab, results)
 
 class ChromeProxyDataSaving(page_test.PageTest):
   """Chrome proxy data saving measurement."""
@@ -677,4 +699,4 @@ class ChromeProxyPingback(ChromeProxyValidation):
       '--enable-stats-collection-bindings')
 
   def AddResults(self, tab, results):
-    self._metrics.AddResultsForPingback(tab, results)
+    self._metrics.AddResultsForPingback(tab, results)

[bustamante, 2016/08/03 19:04:39]

Remove trailing whitespace.

[Robert Ogden, 2016/08/03 21:12:32]

Done.