implement SkScalar versions in terms of float versions

Bug: skia:
Change-Id: I44ce228290f7fda5b7e3553c8543dcf581b1ca3b
Reviewed-on: https://skia-review.googlesource.com/127128
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Mike Reed <reed@google.com>
3 files changed