Partially roll forward of 5c29abbbf4, and adds some extra logic
Changes to the original CL
The original logic (a66f08ba97) fails in the following case:
> This is only seem on emulators.
- EOS is sent to ExtTexMgr
- The timer starts
- One frame arrives on SurfaceTexture, reset the timer
- The frame is sent for processing, now `availablFrames == 0`
- One frame arrives on Surface, reset the timer
- The frame is kept on SurfaceTexture for the downstream shader doesn't have
capacity, `availablFrames == 1`
- Timer times out as the downstream processor doesn't report being able to take
another frame.
- Although there's a frame available on the SurfaceTexture
This is solved by having the force EOS logic clear all the frames that the
SurfaceTexture holds. This also ensures the first frame dequeued from the next
stream isn't from the previous stream.
PiperOrigin-RevId: 540023359
abd96598d9