SDK / exoplayer

tl;dr:
In the previous transformer, the transcoding flow is

- If a the GL's input surface (from decoder) does not have data, wait 10ms
 (DO_SOME_WORK)
- Else, make the decoder render **ONE** frame to the GL's input surface
  - Wait at least 10ms, until the frame's texture is available
  - Then process the texture

The process is quite slow, so in the new version, we do:
- If a the GL's input surface (from decoder) does not have data, wait 10ms
 (DO_SOME_WORK) **same**
- Else, make the decoder render **as many frames** to the GL's input surface
  - Process **as many** available textures in this DO_SOME_WORK cycle

PiperOrigin-RevId: 415474722