GitLab

See the CL: https://codereview.chromium.org/2148723004

BUG=628459
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2175673003
Cr-Commit-Position: refs/heads/master@{#407303}