GitLab

Enable the following as they are consistently green:
* chrome_public_smoke_test
* weblayer_unittests
* webview_ui_test_app_test_apk

Run chrome_public_test_apk at 100% experimentally. According to the bot
usage (http://shortn/_hEy8np3sYC) and swarming tasks status
(http://shortn/_7gxoNS82Qr), the test pool might experience some pending
time. Will keep an eye on it and revert if it causes any issue.
Also disabled 4 flaky tests. See the filter file for details.

Bug: 1111436, 1165449, 1165456, 1165459
Change-Id: Ic1e2a1e431639f8f0ea882f2a412281166222abf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2622006Reviewed-by: Garrett Beaty <gbeaty@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Haiyang Pan <hypan@google.com>
Cr-Commit-Position: refs/heads/master@{#842816}