refusedFrames

Frames a renderer was handed and refused, for example because its surface is gone.

Counted apart from droppedFramesLate, which it used to be folded into. They are different diagnoses with different fixes: a late drop says the pipeline could not keep up, a refusal says the output could not draw, and one number for both made a dead surface read as a slow decoder. A run with a healthy decodedVideoFrames and a rising figure here is a picture problem and nothing else.