more SkBlitter::Choose refactoring
Most of this is just refactoring code and comments to help me keep
the conditions all straight in my head.
I've also sketched the next substantive change I want to make here,
to handle all non-shader/non-SrcOver blits with SkRasterPipelineBlitter.
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I971a31e863247d67fc41f06b67e941bbff3e04a4
Reviewed-on: https://skia-review.googlesource.com/c/167381
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed