[e2e] Use vsyncStart from FrameTiming.

[ditman]

Use case

FrameTiming now provides a vsyncStart value. Update code and tests to account for it. See:

flutter/plugins#2914 (review)

[CareF]

So this will be a very future todo, if we have to keep e2e compatible with the stable version.

[ditman]

Yep, I don't think you want to be assigned to this @CareF until it actually can be done.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.