Chrome version : 68.0.3440.0 (Official Build) 05533d197c5763ecde7fa3dd551fd5ff214cec5e-refs/branch-heads/3440@{#1}(32/64-bit) 
OS:Mac OS X(10.12.6,10.13.1,10.13.5) 

Steps to reproduce:
1.Launch chrome ,open wrench menu and click on cast.
2.Observe .

Actual Result:Cast overlay is seen Blank.
Expected Result:Cast overlay should not be seen blank.

This is regression issue broken in ‘M-68’ and providing per-revision bisect info below:
Good Build:68.0.3439.0(Revision:561389)  
Bad Build:68.0.3440.0(Revision:561733)
 
You are probably looking for a change made after 561716 (known good), but no later than 561717 (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/8803f4e6d8313f0395cce999f0dabe2bad86975c..6f4d713f35161bc425b1032956e2b12fdd5f639f

Suspect:https://chromium.googlesource.com/chromium/src/+/6f4d713f35161bc425b1032956e2b12fdd5f639f

@Christopher Cameron : Could you please help to reassign if your change is not the cause for this change.

Note:Issue is only  reproducible completely on MAC(10.12.6,10.13.1,10.13.5) OS.

Kindly review the attached screen-cast .
Thank You!
 

Deleted: Actual_Result.mov 1.6 MB

	Actual_Result.mov 1.6 MB View Download

Deleted: Expected_Result.mov 1.5 MB

	Expected_Result.mov 1.5 MB View Download