Run WebGL 2.0 conformance tests against Viz changes.

This will increase the likelihood that intermittent failures caused by
changes in this directory will be caught on the commit queue.

Bug: 843290
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Ie4d230c0290706c956d88f483b82b98f3a62f4bf
Reviewed-on: https://chromium-review.googlesource.com/1069598Reviewed-by: Fady Samuel <fsamuel@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560799}

components/viz/PRESUBMIT.py

@@ -19,9 +19,10 @@ def PostUploadHook(cl, change, output_api):
   """git cl upload will call this hook after the issue is created/modified.
 
   This hook modifies the CL description in order to run extra GPU
-  tests (in particular, on Android) in addition to the regular CQ try
-  bots. These tests don't yet run by default on
-  android_n5x_swarming_rel, but viz changes need to run them.
+  tests (in particular, the WebGL 2.0 conformance tests) in addition
+  to the regular CQ try bots. This test suite is too large to run
+  against all Chromium commits, but should be run against changes
+  likely to affect these tests.
 
   When adding/removing tests here, ensure that both gpu/PRESUBMIT.py and
   ui/gl/PRESUBMIT.py are updated.
@@ -29,6 +30,9 @@ def PostUploadHook(cl, change, output_api):
   return output_api.EnsureCQIncludeTrybotsAreAdded(
     cl,
     [
+      'luci.chromium.try:linux_optional_gpu_tests_rel',
+      'luci.chromium.try:mac_optional_gpu_tests_rel',
+      'luci.chromium.try:win_optional_gpu_tests_rel',
       'luci.chromium.try:android_optional_gpu_tests_rel',
     ],
     'Automatically added optional GPU tests to run on CQ.')