Chrome Version:68.0.3440.106 (Official Build) Revision	1c32c539ce0065a41cb79da7bfcd2c71af1afe62-refs/branch-heads/3440@{#794}(64-bit)
OS:Windows(7,8,8.1,10) and Mac(10.12.6, 10.13.1, 10.13.6, 10.14).

Test URL:https://mounirlamouri.github.io/sandbox/media/dynamic-controls.html

Steps to reproduce:
1.Launch chrome and Navigate to above URL.
2.Open Devtools and change devtools theme to 'dark' from settings.
3.Run Audit and observe.

Actual Result:Some portion of page turns black after performing audit on it.
Expected Result:No such portion should be seen black after performing audit on Test URl.

This is a regression issue, broken in 'M-65', and below is per-revision bisect-info:
Good Build:65.0.3324.0(Revision:530028)
Bad Build: 65.0.3325.0(Revision:530369)

You are probably looking for a change made after 530033 (known good), but no later than 530034 (first known bad).
CHANGE-LOG URL:
The script might not always return single CL as suspect as some perf builds might get missing due to failure.
  https://chromium.googlesource.com/chromium/src/+log/3ad51612ce8cd153c47dda9ea3fca5051efbab04..d8720c79319084a462f6db65f58f24be65639815

Suspect:https://chromium.googlesource.com/chromium/src/+/d8720c79319084a462f6db65f58f24be65639815

@Jianzhou Feng: Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.
Note:As Jianzhou Feng is oo, requesting Dmitry Gozman for this issue and hence keeping  in cc.

Kindly refer the attached screen-cast 
Thank You.
 

Deleted: Actual_Result.mp4 755 KB

	Actual_Result.mp4 755 KB View Download

Deleted: EXPECTED_RESULT.mp4 1.0 MB

	EXPECTED_RESULT.mp4 1.0 MB View Download