This is a simpler and more portable design. Thanks for Austin from MS.

BUG=angleproject:1452

Change-Id: I93e8f3fc61107f13c4b2c1cf7fbaf2bb7ccdfafb
Reviewed-on: https://chromium-review.googlesource.com/363041Reviewed-by: Austin Kinross <aukinros@microsoft.com>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>