[hwcomposer] Don't waitVsync if we haven't activated vsync yet

Review Request #126083 - Created Nov. 16, 2015 and submitted

Martin Flöser
Would just hit the timeout, no need to wait 16 msec for nothing.

[hwcomposer] Add support for backlight through light_device_t

We use the hw module's backlight and set the color to either 0
or FF depending on whetehr we want to have the screen on or off.
This turns the backlight off properly. It is bound to the toggleBlank
functionality so that we always turn on/off the backlight depending
on whether our compositor is on or off.

In addition we listen to key release events on the power button to
toggle the state.

Bhushan Shah
Marco Martin
Bhushan Shah
Martin Flöser
Review request changed

Status: Closed (submitted)

Change Summary:

Submitted with commit e71a230213db70cd834565002ebda48853145146 by Martin Gräßlin to branch master.