GitLab

This is a reland of 75391394.

Reason for reland:
- Fixed a flaky test failures in crrev.com/c/2309317
- No changes in this CL between original & reland.

Original change's description:
> Convert WidgetMsg_WaitForNextFrameForTest to mojo
>
> This CL uses VisualStateRequest Mojo API in FrameWidget mojo interface
> introduced at https://crrev.com/c/2178480 since
> WidgetMsg_WaitForNextFrameForTest has the same implementation with
> VisualStateRequest Mojo API notifying that the frame swap has occurred.
>
> Bug: 1071588
> Change-Id: If317b98320ec3fb85fcf7a5d1e39f0fa202d4cde
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2216145
> Commit-Queue: Miyoung Shin <myid.shin@igalia.com>
> Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
> Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#789910}

Bug: 1071588
Change-Id: I7ade2819495cddf87862054095db361e0511dcf5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2309497
Commit-Queue: Miyoung Shin <myid.shin@igalia.com>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#793839}