Revert "Revert "Revert "SurfaceFlinger: give SF its own vsync phase"""

This reverts commit d5ee2ff1b9a2abd12a3a192a64a469201f9c11fb.

Conflicts:

	services/surfaceflinger/SurfaceFlinger.cpp

Change-Id: I789dcdb72510daef1a1a3530ffd9164aefeef845