GitLab

This CL extracts CreateSurface() and SurfaceReady() into a new
interface: DecodeSurfaceHandler.  This extraction reduces the
coupling surface (always good) and allows e.g. easier testing in
subsequent CLs.

VaapiVideoDecodeAccelerator is made to implement the said
templatised interface and teaches the Vaapi*Accelerator classes
to use it (instead of the whole VaVDA).

Partial diagram before: https://goo.gl/LBxH3h, after: https://goo.gl/E6sDrc.

Test: v_d_a_unittests and simplechrome on nautilus
Bug: 875005
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Id376a6a25e664b0b6669b202062ebd7179346c50
Reviewed-on: https://chromium-review.googlesource.com/1178340
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586680}