This is a temporary home for the various workarounds we use
for performance or to solve driver issues. Eventually we will
want a standalone library we can use as part of Chromium or
in ANGLE standalone.

Re-land with member variable initialized.

BUG=angle:729

Change-Id: If7f8f9596a39b2855366d9a67caebf6dd4197b55
Reviewed-on: https://chromium-review.googlesource.com/219868Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>