It is now possible to say:
dumpsys SurfaceFlinger --latency
to print latency information about all windows
dumpsys SurfaceFlinger --latency window-name
to print the latency stats of the specified window
for instance: dumpsys SurfaceFlinger --latency SurfaceView
The data consists of one line containing global stats, followed by
128 lines of tab separated timestamps in nanosecond.
The first line currently contains the refresh period in nanosecond.
Each 128 following line contains 3 timestamps, of respectively
the app draw time, the vsync timestamp just prior the call to set and
the timestamp of the call to set.
Change-Id: Ib6b6da1d7e2e6ba49c282bdbc0b56a7dc203343a