wmatrix: PSA to recommend migration to Stainless.

BUG=b:69277926
TEST=run locally

Change-Id: I907ce4dd77e6729aa8ec1f9897d7044f3d493916
Reviewed-on: https://chromium-review.googlesource.com/768524
Commit-Ready: Shuhei Takahashi <nya@chromium.org>
Tested-by: Shuhei Takahashi <nya@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
3 files changed