Update related bug IDs for expected WebGL 2 conformance test failures.

BUG=
TEST=
TBR=kbr@chromium.org
NOTRY=true
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2039063002
Cr-Commit-Position: refs/heads/master@{#397932}
1 file changed