remove unneeded friends/includes in SkPaint.h Bug: skia: Change-Id: Ica9f10cdb67322eb43ec38b6549146350fa5dcd9 Reviewed-on: https://skia-review.googlesource.com/c/188630 Commit-Queue: Mike Reed <reed@google.com> Reviewed-by: Mike Reed <reed@google.com> Auto-Submit: Mike Reed <reed@google.com>