Refactor VDA unittest to have a base class for simple VDA client, and use super classes for different testing scenarios. Like VEA unittest:
https://cs.chromium.org/chromium/src/media/gpu/video_encode_accelerator_unittest.cc?q=video_encode_accelerator_unittest+package:%5Echromium$&dr&l=1772

Also, add a check for number of decoded frame before client sends reset to decoder should be not greater than video frames.