Explicitly disable LayoutNG for web_tests

Explicitly disable the LayoutNG runtime enabled feature for web_tests if
not explicitly enabled to allow the feature to be toggled without having
to update thousands of expectations each time. Once stable, results will
be updated one bot at a time by explicitly enabling the feature per bot.

This logic will be removed once LayoutNG has been enabled for every bot.

Bug: 961437
Change-Id: Ia823ba0f92817e0c8ee0250bb4c662f0efdabe4e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1603528
Reviewed-by: Stefan Zager <szager@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Emil A Eklund <eae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658712}
1 file changed