Remove unused code
Remove unused code

Stats can be collected through the tool of aom_entropy_optimizer using
the dumped file counts.stt.

Change-Id: I121fb6f819841fe09e304c11f83113b27c73afdd

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom