BUG=angleproject:1161

This is a continuation of the dirty bit refactor

Change-Id: I1a9f297835943eee5f756e4e4721b2db543184ec
Reviewed-on: https://chromium-review.googlesource.com/312987Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Dian Xiang <dianx@google.com>