GitLab

Replace modesetting displays using Legacy APIs to use Atomic Commit APIs
for enabling and disabling screens.
The flow for modeset follows closely the flow for atomic page flip.
Change only apply to devices supporting Atomic APIs. Legacy APIs are
still used by older systems.
Tests are improved to accommodate for props being set on modeset and an
extra commit being called.

(Reland of "Ozone: Implement Atomic Modeset" reverted on crrev.com/c/2152766)

BUG=987274
TEST=Enable and Disable displays, ozone_unittests

Change-Id: I452b271c5bf2d6b67151c08fe81933e4bc20e9f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2415050Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Commit-Queue: Mark Yacoub <markyacoub@google.com>
Cr-Commit-Position: refs/heads/master@{#807889}