Using the per-revision bisect providing the bisect results,
Good build:59.0.3065.0 (Revision:462712).
Bad build: 59.0.3066.0 (Revision:463122).
CHANGELOG URL:
https://chromium.googlesource.com/chromium/src/+log/311b4ebadca3e47753627f385ee4ce3482331404..258527ddc93825a5feac1bd3de5f5efb8d975856

Review-Url: https://codereview.chromium.org/2806703002

@guidou: Could you please look into the issue, pardon me if it has nothing to do with your changes and if possible please assign it to concern owner.
Thank You.

I'm looking into the issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/71ffa0d2e073d09d8098b0794f7f382655aabedc

commit 71ffa0d2e073d09d8098b0794f7f382655aabedc
Author: guidou <guidou@chromium.org>
Date: Mon Apr 10 17:26:49 2017

Update selection of resolution policy for screen capture with getUserMedia.

The intent of the new algorithm is to allow resolution adjustment if the
resolution range allowed by constraints is a superset of the capabilities.
However, the actual capabilities are not currently known and, in practice,
resolution adjustment was allowed only when no constraints were specified.

This CL relaxes this rule to allow resolution adjustment by treating a max
constraint as if it were the actual capability. This should be updated so
that the actual native screen resolution is used as capability, but, in the
meantime, this fix is more compatible with existing applications that expect
the behavior of the old algorithm. Moreover, this patch does not affect spec
compliance since screen-resolution policies are not regulated by the spec as
long as the output resolution is within the constrained range.

BUG= 709915 

Review-Url: https://codereview.chromium.org/2800343005
Cr-Commit-Position: refs/heads/master@{#463309}

[modify] https://crrev.com/71ffa0d2e073d09d8098b0794f7f382655aabedc/content/renderer/media/media_stream_constraints_util_video_content.cc
[modify] https://crrev.com/71ffa0d2e073d09d8098b0794f7f382655aabedc/content/renderer/media/media_stream_constraints_util_video_content_unittest.cc

This is fixed in r463309.
When verifying, please don't compare with 59.0.3065.0, but with 59.0.3064.0 or older.
There is a bug in 59.0.3065.0 that makes it capture at 640x480 in most cases, which produces a smaller image than usual, which makes it faster. Thus, this is not the right baseline.
59.0.3066.0 on the other hand was capturing at a larger resolution than usual, which made it slightly slower.
The fix restores capture resolution to what it was in 3064 and before.

Tested the issue on Win 7 Using 59.0.3071.9 and the animation is smooth now on opening Report an issue Overlay.

Please find the attached screen cast

Deleted: 709915.mp4 463 KB

	709915.mp4 463 KB View Download