Unclear why this wasn't reproducing on our integrated tests. Seems to
affect most Vulkan tests.

Regression likely introduced with the multithreading code.

Bug: angleproject:2464
Change-Id: I62a0c1a4f5e5bf63efdef2a979d9b2efb6a1ea81
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1864314
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>