Expand testing of SkMatrix::decomposeScale

Bug: skia:7211
Change-Id: If03ad1d364b33e174d91010ca250cd6c2d2f67c2
Reviewed-on: https://skia-review.googlesource.com/140185
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
4 files changed