unguard SkFooEncoder.cpp

We used to define SkFooEncoder::Encode() either
here or as failing stubs in SkImageEncoder.cpp.

Now that we're not defining them in SkImageEncoder.cpp,
we can lift these guards here.

Change-Id: Id916811225450e4c3a84f1e7f38ae510be1d6268
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/214004
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
3 files changed