[DL]: Update display locking to use the revised API.

This patch replaces acquireDisplayLock() and all associated context
operations with getDisplayLock() and three ops:
- acquire
- update
- commit.

R=chrishtr@chromium.org

Bug: 882663
Change-Id: I7e85a3d164538f826a411498e1cddcf58a4c70a1
Reviewed-on: https://chromium-review.googlesource.com/c/1378669
Commit-Queue: vmpstr <vmpstr@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618283}
72 files changed