Before this CL, SurfaceTexture.onFrameAvailable was used to tell whether a frame
was available in the VideoFrameProcessor's output texture. This was incorrect, as
it would rely on having the texture be written to before the
SurfaceTexture.onFrameAvailableListener is invoked, leading to null-pointer-
exceptions on timeouts.
Instead of using DefaultVideoFrameProcessor different interfaces to set that we
want to output to a texture, and get that output texture, use one interface that
sets a listener, and renders to a texture iff that listener is set. As this
listener is executed on the GL thread, this also allows us to no longer need to
expand visibility for the GL task executor and tasks.
PiperOrigin-RevId: 522362101
0d30edae75