Revert of remove colorfilter native-565 support. complicating w/ no real value. ...

Revert of remove colorfilter native-565 support. complicating w/ no real value. (patchset #2 id:20001 of https://codereview.chromium.org/1015533011/)

Reason for revert:
skia/ext/benchmarking_canvas.cc references HasFilter16 :(

Original issue's description:
> remove colorfilter native-565 support. complicating w/ no real value.
>
> BUG=skia:
> TBR=
>
> Committed: https://skia.googlesource.com/skia/+/2151353d161fe389cdc0db62cfe1932c7680f710

TBR=reed@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1022673007