Manual regression range:
Good Build: 48.0.2559.0
Bad Build: 48.0.2561.0

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/e026f4038aeb0b33904241654375e1a2d1afd9cb..1945f47a23f8ef417702d535e3f7365bba4d5138?pretty=fuller&n=50

Suspecting: 358911 or 358917 ?
Kindly help to re-assign, if your changes are not cause for this issue.

Note: Issue not seen on Win & Linux OS.

Deleted: Actual_Result.mov 6.1 MB

Actual_Result.mov 6.1 MB Download

Deleted: Expected_Result.mov 2.8 MB

Expected_Result.mov 2.8 MB Download

Marking the above issue as RB-Stable, feel free to remove if not required.

Thank you!

The site does not use the webkit-border properties from r358911, so I doubt it is my chance. If this is Mac only problem then it makes more sense to hunt for Mac specific changes.

Issue still persists on latest canary 53.0.2753.0.
eugenebut @ : cced you suspecting if its related to your below change.Can you please take a look into the same.
https://codereview.chromium.org/1416743008

My change was in ios/ directory, which should not be used on Mac platform.

CHANGELOG URL: https://chromium.googlesource.com/chromium/src/+log/48.0.2559.0..48.0.2561.0?pretty=fuller&n=10000

Suspecting Commit: 529873b0d9581a1981717383d6066a1a9dbfa52f	

Review URL: https://codereview.chromium.org/1413493005

@ymalik: Could you please look into the issue, and if it has nothing to do with your changes and if possible please do assign it to the concerned owner.

Thank you.

My change only affects Windows.

I have no idea what could have caused this among the bisect results, but it's
definitely not 529873b0d9581a1981717383d6066a1a9dbfa52f.

Olivia, could you try to narrow down to the CL which broke it on Mac via manually trying git revisions?

Moving this nonessential bug to the next milestone.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

CL: https://chromium.googlesource.com/chromium/src/+log/485adb2901e3fcd0adc45ac399c310e1c4a76498..e026f4038aeb0b33904241654375e1a2d1afd9cb

From above CL, suspecting below:
https://chromium.googlesource.com/chromium/src/+/e026f4038aeb0b33904241654375e1a2d1afd9cb

spqchan@; Could you please look into this issue if it is related to your change, else feel free to reassign it to an appropriate dev person.

This issue is Pri-1 but has already been moved once. Lowering the priority and moving to the next milestone.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Assigning to sdy@ who is working with fullscreen