Fix commit id versioning when building with Chrome. The GYP syntax would cause problems with the ninja build. BUG=angle:529 Change-Id: I84a30afc9bd8900535e44f5d5f9d8f766a4686e8 Reviewed-on: https://chromium-review.googlesource.com/186610 Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/186984 Reviewed-by: Nicolas Capens <nicolascapens@chromium.org>