Revert "Revert "add tiler for SkDraw"" This reverts commit 461ef7af88cc966007c464130a971ec86c803f1d. Prev CL to SkScan_Hairline.cpp fixed the bug that caused the earlier revert. Bug: skia: Change-Id: Ifd9a364c7546175be292f726e19465b72196b45e Reviewed-on: https://skia-review.googlesource.com/112723 Reviewed-by: Mike Reed <reed@google.com> Commit-Queue: Mike Reed <reed@google.com>