libstagefright: Render video frames on vsync

Render video frames on vsync, which helps to
synchronize display and decoder activity, and
reduces power consumption

CRs-Fixed: 649540
Change-Id: I0981d7723621de963d22f7fd7ca0eed48f016090

Conflicts:
	media/libstagefright/AwesomePlayer.cpp
	media/libstagefright/ExtendedUtils.cpp