Remove obsolete paint copy

All the backends use the glyph run natively now, and
glyph runs never interpret these fields in paint.

Change-Id: I1c6fde1202057391e3a3f9be65f1e8a851205df5
Reviewed-on: https://skia-review.googlesource.com/158720
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Herb Derby <herb@google.com>