Remove ambient and spot mask filters.

Also remove a deprecated interface in SkShadowUtils.

Change-Id: I32e67271be953f11071c512cb39a47ea1e7dcaaf
Reviewed-on: https://skia-review.googlesource.com/17266
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
10 files changed