suspend fun beginFrame(input: BeginFrameRequest): BeginFrameResponse
Sends a BeginFrame to the target and returns when the frame was completed. Optionally captures a screenshot from the resulting frame. Requires that the target was created with enabled BeginFrameControl. Designed for use with --run-all-compositor-stages-before-draw, see also https://goo.gl/3zHXhB for more background.