Remove old lazy image decoding heuristic logic

This led to removing a lot of transfer function behavior code. There is
more that could be done, and we need to add in decoding to dst color
space, but this CL is almost entirely mechanical.

Change-Id: I91b2169f95aadcfaacdd2b9821bb1a01ce53f9a6
Reviewed-on: https://skia-review.googlesource.com/140349
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
15 files changed