Revert "Remove WaitSyncTokenCHROMIUM command"

This reverts commit c19106d109d4d36871c11bfb5a683d222583dd15.

Reason for revert: Causing multiple mac gpu fyi failures

Original change's description:
> Remove WaitSyncTokenCHROMIUM command
> After migrating InProcessCommandBuffer to use GPU scheduler, most tasks
> are scheduled after their sync token dependencies are satisifed (see
> The one exception was the WaitSyncToken IPC used by ReturnFrontBuffer
> for pepper, which specifies a sync token, and waits while handling the
> message.
> Change ReturnFrontBuffer to contain the sync token, and use it to
> specify the dependency to the scheduler.
> Remove WaitSyncTokenCHROMIUM command, since sync token dependencies are
> specified as task metadata in all cases.
> Make other cleanups such as removing unnecessary sync token tests, and
> make sure the sync token code paths are not used where unsupported by
> 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: Ieee4f6e2427a59a4e0c4b3c983cb489741241272
> Bug: 778753
> Reviewed-on:
> Reviewed-by: Bo <>
> Reviewed-by: Daniel Cheng <>
> Reviewed-by: Antoine Labour <>
> Commit-Queue: Sunny Sachanandani <>
> Cr-Commit-Position: refs/heads/master@{#599849},,,

Change-Id: I87347c05dded27955410b08e40f37388a484d5f9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 778753, 895984
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
Reviewed-by: Sunny Sachanandani <>
Commit-Queue: Sunny Sachanandani <>
Cr-Original-Commit-Position: refs/heads/master@{#600102}
Cr-Mirrored-Commit: 063f6d2a2897dcfb9afc3ee80cbb78ef87e9fe2a
2 files changed