Guard GrOp::dumpInfo with SK_DEBUG

This code was only called from debug code, but was still showing up in
Flutter's release build.

Bug: skia:
Change-Id: I0cba323fc3cb14cfe6daf2388cecf5cf317ac9fa
Reviewed-on: https://skia-review.googlesource.com/c/170268
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
42 files changed