Add SkSurfaceCharacterization operator== && !=

TBR=bsalomon@google.com
Change-Id: Ic58849dcb3be1f00431f897af328f6f3c3f00d75
Reviewed-on: https://skia-review.googlesource.com/118340
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
5 files changed