Merge SkFooAdapterCodec impls into one impl

Bug: skia:
Change-Id: I5071e45979c1bbfc56ad994367a039390e2519f9
Reviewed-on: https://skia-review.googlesource.com/c/169920
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
7 files changed