Pull over the more recent changes from Chromium which include the
graphics API, which we can use for specific API suppressions for
the dEQP tests.

Also update the docs with detailed steps for updating from Chrome.

BUG=None

Change-Id: I0cb7d8268fbb2778c0160a58f1a10ef4a92c9c61
Reviewed-on: https://chromium-review.googlesource.com/287810Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>