Reland "remove toString"

This reverts commit 32a4910e57b1fdd3c8671de1ee85e05ca21d079f.

Reason for revert: SkMatrix::toString use has been removed from flutter and has been picked up in fuchsia

Original change's description:
> Revert "remove toString"
> 
> This reverts commit 5191880cbf3ee4d122b0d11b4945fbab0784fda7.
> 
> Reason for revert: broke flutter
> 
> Original change's description:
> > remove toString
> > 
> > toString may have been used by obsolete debugger only
> > find out if that is so
> > 
> > R=​brianosman@google.com,bsalomon@google.com
> > 
> > Docs-Preview: https://skia.org/?cl=119894
> > Bug:830651
> > Change-Id: I737f19b7d3fbc869bea2f443fa3b5ed7c1393ffd
> > Reviewed-on: https://skia-review.googlesource.com/119894
> > Commit-Queue: Cary Clark <caryclark@google.com>
> > Reviewed-by: Brian Salomon <bsalomon@google.com>
> 
> TBR=bsalomon@google.com,brianosman@google.com,caryclark@google.com,caryclark@skia.org
> 
> Change-Id: I9f81de6c3615ee0608bcea9081b77239b4b8816c
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 830651
> Reviewed-on: https://skia-review.googlesource.com/129340
> Reviewed-by: Cary Clark <caryclark@google.com>
> Commit-Queue: Cary Clark <caryclark@google.com>

TBR=bsalomon@google.com,brianosman@google.com,caryclark@google.com,caryclark@skia.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 830651
Change-Id: Ida8725b6051132d8c46faf99358a8fcc1bcabf34
Reviewed-on: https://skia-review.googlesource.com/129623
Reviewed-by: Cary Clark <caryclark@skia.org>
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Cary Clark <caryclark@google.com>
130 files changed