GitLab

As ANGLE makes more extensions enableable (and disabled by default for
WebGL contexts), they need to be requested by the passthrough command
decoder in order to maintain the same functionality.  Eventually these
extensions can be requested from WebGL once the command buffer client is
aware of the functionality.

BUG=angleproject:1523

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:win_optional_gpu_tests_rel
Change-Id: I91194b32efc7df0fe340dcd5f52e4fc1dcd59e62
Reviewed-on: https://chromium-review.googlesource.com/687534
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504837}