If all subencoders support textures, the adapter will claim support. Texture frames will be passed on directly to subencoders, without any attempt at scaling, and subencoders will be expected to sample/scale correctly from source textures. BUG= NOTRY=true Review-Url: https://codereview.webrtc.org/2099483002 Cr-Commit-Position: refs/heads/master@{#13365}