Alexandros Frantzis authored Sep 27, 2017 and Pekka Paalanen committed Sep 29, 2017

Use EGL fence sync objects to emit timepoints for the beginning and the
end of rendering on the GPU. The timepoints are emitted asynchronously
using the sync file fds associated with the fence sync objects. The sync
file fds are acquired using the facilities provided by the
EGL_ANDROID_native_fence_sync extension.

The asynchronous timepoint submissions are stored in a list in
gl_output_state until they are executed, and any pending submissions
that remain at output destruction time are cleaned up.

If timelining is inactive or the required EGL extensions are not
present, then GPU timepoint processing and emission are skipped.

Note that the GPU timestamps returned by sync files are in the
CLOCK_MONOTONIC clock domain, and are thus compatible with the
timeline timestamps (which also are in the CLOCK_MONOTONIC domain).

Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>