This is no longer necessary with the removal of the submit fence.

Bug: b/172704839
Change-Id: If8c2795d7e3c73453a235498ed6caac727bdaca5
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2524549
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>