The four new tests are added here: https://chromium-review.googlesource.com/c/chromium/src/+/1359953

For now, I will disable them on Android and land the tests, so we could have some coverage on other platforms, but we should not let them stay disabled on Android.

See issue 858826 too

I have a CL in CQ to reenable the MP4 and VP9 tests everywhere except Android: https://chromium-review.googlesource.com/c/chromium/src/+/1214364

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/161f3975469bb19a3c2f3ef62dda1d58457f3691

commit 161f3975469bb19a3c2f3ef62dda1d58457f3691
Author: Zhenyao Mo <zmo@chromium.org>
Date: Wed Dec 05 03:30:00 2018

Add GPU pixel tests for MP4 videos with rotation and aspect specified.

BUG=911413,911895,911898
TEST=GPU bots, pixel
R=sunnyps@chromium.org,kbr@chromium.org

Change-Id: I2971656ae3f78c2ac62ebc4a2239d491fa438528
Reviewed-on: https://chromium-review.googlesource.com/c/1359953
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613849}
[modify] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/chrome/test/BUILD.gn
[add] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/content/test/data/gpu/pixel_video_mp4_four_colors_aspect_4x3.html
[add] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/content/test/data/gpu/pixel_video_mp4_four_colors_rot_180.html
[add] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/content/test/data/gpu/pixel_video_mp4_four_colors_rot_270.html
[add] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/content/test/data/gpu/pixel_video_mp4_four_colors_rot_90.html
[modify] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/content/test/gpu/gpu_tests/pixel_expectations.py
[modify] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/content/test/gpu/gpu_tests/pixel_test_pages.py
[modify] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/media/test/data/README.md
[add] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/media/test/data/four-colors-aspect-4x3.mp4
[add] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/media/test/data/four-colors-rot-180.mp4
[add] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/media/test/data/four-colors-rot-270.mp4
[add] https://crrev.com/161f3975469bb19a3c2f3ef62dda1d58457f3691/media/test/data/four-colors-rot-90.mp4