remove device field from SkDraw

BUG=skia:6214

Change-Id: I5d57feb3e92f2c1691231c982e74020560febeca
Reviewed-on: https://skia-review.googlesource.com/8837
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
7 files changed