Drops a tile presented earlier: the TileScheduler calls it to keep the tiles a surface holds within its memory budget, and counts the tile's pixels as freed once it returns. Called on the thread that runs the scheduler's frames, or (in background mode) on the worker that just presented a tile.
void Evict(Tile tile)
A tile passed to Present(Tile, Bitmap) before and not dropped since.
Spec #33 viewer capability 13. The default does nothing, for surfaces that keep no tiles.