The Matrices test now verifies its results.

Previously, this test did a bunch of matrix math but never actually
checked its results for correctness.

Change-Id: I353be58049286266c2d561b0939b3874d2684403
Bug: skia:11985
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/407360
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
4 files changed