media/gpu/image_processor_test: Initial version of image_processor_test

image_processor_test is a test for ImageProcessor. The tested
image processor is platform-dependent and decided on the capability.
The initial version of image_processor_test tests one video frame conversion
from I420 (Memory) to NV12 (Memory).

Bug: 917951
Test: ImageProcessorTest on Linux and Chrome OS
Change-Id: Ie81a6728ab073a164daa18411d45093caf872efb
Reviewed-on: https://chromium-review.googlesource.com/c/1391664
Commit-Queue: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: David Staessens <dstaessens@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625069}
6 files changed