Move DrawToTargetWithShapeMask to GrSoftwarePathRenderer

That function has nothing to do with software masks - I claim it was only
in GrSWMaskHelper because it was used by the software path renderer.

Also trimmed some includes.

Bug: skia:
Change-Id: I6939010c70309cdc4135cb250afe85ad7b7be451
Reviewed-on: https://skia-review.googlesource.com/35821
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
6 files changed