DO NOT MERGE: drm_hwcomposer: Introduce Planner interface am: d9c3e2d9c8  -s ours
am: 4258a8a169

* commit '4258a8a169938f1dca4bb61f2ea939dac38a0ff4':

Change-Id: I6ea4a19a0f3623e42aecfd47a5724a320c37cd91