The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1e336d09d716d4a001ef2e08b7699b856af7e9c7

commit 1e336d09d716d4a001ef2e08b7699b856af7e9c7
Author: Jeff Carpenter <jeffcarp@chromium.org>
Date: Tue May 23 00:17:17 2017

[WPT Export] Filter and transform paths for patches from Gerrit

We're getting CL patches raw from Gerrit, which means we were trying
to take a patch with non-exportable changes and apply it wholesale
to WPT. This fixes that problem by filtering all Gerrit patches
and removing the Chromium WPT directory prefix from all applicable
files in the patch.

Bug:  722435 
Change-Id: I1e7e27fabddbb6c2d4d2851c4c9a4b1426893d05
Reviewed-on: https://chromium-review.googlesource.com/506559
Commit-Queue: Jeff Carpenter <jeffcarp@chromium.org>
Reviewed-by: Quinten Yearsley <qyearsley@chromium.org>
Cr-Commit-Position: refs/heads/master@{#473758}
[modify] https://crrev.com/1e336d09d716d4a001ef2e08b7699b856af7e9c7/third_party/WebKit/Tools/Scripts/webkitpy/w3c/gerrit.py
[add] https://crrev.com/1e336d09d716d4a001ef2e08b7699b856af7e9c7/third_party/WebKit/Tools/Scripts/webkitpy/w3c/gerrit_unittest.py
[add] https://crrev.com/1e336d09d716d4a001ef2e08b7699b856af7e9c7/third_party/WebKit/Tools/Scripts/webkitpy/w3c/resources/expected.patch
[add] https://crrev.com/1e336d09d716d4a001ef2e08b7699b856af7e9c7/third_party/WebKit/Tools/Scripts/webkitpy/w3c/resources/sample.patch
[modify] https://crrev.com/1e336d09d716d4a001ef2e08b7699b856af7e9c7/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter_unittest.py

Change landed but is unverified. Will reopen if any CLs come up that should be PR'd but aren't.