Revert "[Media UX] Enable the pixel by pixel comparison test for Mac OS."

This reverts commit 0cfecb52487066ad0cc55ccf18635e6d28bd9b5d.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 606552 as the
culprit for flakes in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/flake/flake-culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyQwsSDEZsYWtlQ3VscHJpdCIxY2hyb21pdW0vMGNmZWNiNTI0ODcwNjZhZDBjYzU1Y2NmMTg2MzVlNmQyOGJkOWI1ZAw

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.mac/Mac10.12%20Tests/16586

Sample Failed Step: network_service_browser_tests on Intel GPU on Mac on Mac-10.12.6

Sample Flaky Test: PictureInPicturePixelComparisonBrowserTest.VideoPlay

Original change's description:
> [Media UX] Enable the pixel by pixel comparison test for Mac OS.
> 
> 1. Tested on Mac and verify everything works as expected.
> 2. Removed the unnecessary call of GetNativeWindow().
> 3. The RGB for GPU enabled and GPU disabled test images is slightly different. Additional check is needed.
> 
> Bug: 898230
> Change-Id: I85bf2450862361572597632159de60db6abf2c22
> Reviewed-on: https://chromium-review.googlesource.com/c/1307062
> Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
> Commit-Queue: Clifford Cheng <cliffordcheng@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#606552}

Change-Id: I10a133230cad3256bf4e5e0c3c925920484ce6a1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 898230, 903580
Reviewed-on: https://chromium-review.googlesource.com/c/1327612
Cr-Commit-Position: refs/heads/master@{#606647}
1 file changed