Revert "Revert "Spot shadow cleanup and optimization""

This reverts commit aa2bd8f726d98edafd28c8553e99cbae33c431dd.

Change-Id: Iaa5d9e649d842889ff031eeb11d0547270968420
Reviewed-on: https://skia-review.googlesource.com/7981
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed