@ kStrict_SrcRectConstraint
sample only inside bounds; slower
static SkMatrix Scale(SkScalar sx, SkScalar sy)
bool mapRect(SkRect *dst, const SkRect &src, SkApplyPerspectiveClip pc=SkApplyPerspectiveClip::kYes) const
#define DEF_SIMPLE_GM(NAME, CANVAS, W, H)
static SkRect Make(const SkISize &size)