GitLab

When creating a plane for modeset, ensure that the plane buffer modifier matches
the modifier we will use in the next page flip, which is created
through the list of preferred modifiers.
Also, pass the preferred modifiers list to GetModesetBuffer() so it could be manipulated for modeset tests.

BUG=979736
TEST=The modifier of the buffer used in Modeset matches the consequent page flip.

Change-Id: I59d5c499961b093f06c19e513a96f49dde471c4a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2463363Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Commit-Queue: Daniele Castagna <dcastagna@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816591}