Add methods for converting GrShape to filled style

Bug: skia:
Change-Id: I6726428d1358909972adec8d63686b637ef5bb5e
Reviewed-on: https://skia-review.googlesource.com/40222
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
3 files changed