Refactoring patch only, should have no externally visible changes.

BUG=angle:466

Change-Id: I01088a3b2979b96702d0a3c424d26928eb72b5b2
Reviewed-on: https://chromium-review.googlesource.com/203731Reviewed-by: Nicolas Capens <nicolascapens@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>