BUG=638327
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win10_chromium_x64_rel_ng;master.tryserver.chromium.win:win_optional_gpu_tests_rel

TBR=dalecurtis@chromium.org, reillyg@chromium.org, sdefresne@chromium.org, thakis@chromium.org
Mechanical substitutions.

Review-Url: https://codereview.chromium.org/2830893004
Cr-Commit-Position: refs/heads/master@{#466416}