This reverts commit 1b0f79ee.

Reason for revert: Breaks a number of applications on Android

Original change's description:
> Vulkan: Use atomics in SerialFactory.
>
> This allows serials to be generated from multiple threads without locking for
> very little/no cost.
>
> BUG=angleproject:2464
>
> Change-Id: Id61d170e7a985c3100da0057156859ffcb083dad
> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1516514
> Commit-Queue: Geoff Lang <geofflang@chromium.org>
> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>

TBR=geofflang@chromium.org,syoussefi@chromium.org,jmadill@chromium.org

Change-Id: I52011f294d68490998869fa898e929fd41eaa51c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1636272Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Cody Northrop <cnorthrop@google.com>