[graphite] Add support for the ImageShader's local matrix

Unsurprisingly, this makes more of the GMs and SKPs look correct.

It isn't added exactly as we would like going forward though. I
believe we would prefer something that munges the matrix and then
calls a child.

Bug: skia:12701
Change-Id: Ib50246a8d575a8a2489afdb7e5f6032a22637bd2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/535116
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
7 files changed