Reland "Allow rect and circle blur fast cases to be used with rotation matrices."

This is a reland of 2bded27a961b4d301f2d8d88829b164fa35714ef

Original change's description:
> Allow rect and circle blur fast cases to be used with rotation matrices.
>
> For circles this is trivial. The existing shader works as is.
>
> For rects this requires back projecting from device space.
>
> Adds a GM for rotated rect blurs and modifies a circle blur GM to add
> rotation.
>
> Bug: chromium:1087705
>
> Change-Id: I6b969552fbcc9f9997cfa061b3a312a5a71e8841
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/318757
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

Bug: chromium:1087705
Change-Id: Ie3ef96c40461665f6207225a15e19b4cf5bcba94
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/319338
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
7 files changed