New debugging tool in adb shell dumpsys gfxinfo

This tool lets you visualize the time it took, in ms, to:
- Build display lists ("Draw" phase)
- Process display lists ("Process" phase)
- Swap GL buffers ("Execute" phase)

To use this tool:
- adb shell setprop hwui.profile true
- adb shell dumpsys gfxinfo <process name>
- Copy the profile data and paste it in a spreadsheet
- Generate a graph (stacked graph) and enjoy

Change-Id: I7840c0ea0f153550425aa798e3ada2f357688cf5