The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ee873e760f26ecebde137f160a2673ae83359bd3

commit ee873e760f26ecebde137f160a2673ae83359bd3
Author: sclittle <sclittle@chromium.org>
Date: Tue Mar 14 20:16:58 2017

Add Data Saver ChromeDriver test for MissingViaHeader4xx bypass behavior

This test attempts to load a page through a test proxy that doesn't set
the via header properly on a 4xx-error response, and verifies that
Chrome bypasses all proxies and retries the request over direct.

BUG= 700612 

Review-Url: https://codereview.chromium.org/2742693006
Cr-Commit-Position: refs/heads/master@{#456809}

[modify] https://crrev.com/ee873e760f26ecebde137f160a2673ae83359bd3/tools/chrome_proxy/webdriver/bypass.py

This test is flaky, failing about half the time with

======================================================================
FAIL: testMissingViaHeader4xxBypass (bypass.Bypass)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/local/google/home/robertogden/chromium/src/tools/chrome_proxy/webdriver/bypass.py", line 135, in testMissingViaHeader4xxBypass
    self.assertEqual(1, histogram['count'])
AssertionError: 1 != 2

Please fix when you get the chance

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c37ea25b3d66e0081c0fc86c3a24e4e38c48177b

commit c37ea25b3d66e0081c0fc86c3a24e4e38c48177b
Author: ryansturm <ryansturm@chromium.org>
Date: Wed Apr 12 23:44:16 2017

Fixing flaky integration test

BUG= 700612 

Review-Url: https://codereview.chromium.org/2816823002
Cr-Commit-Position: refs/heads/master@{#464207}

[modify] https://crrev.com/c37ea25b3d66e0081c0fc86c3a24e4e38c48177b/tools/chrome_proxy/webdriver/bypass.py

Working consistently now, thanks!