Experimental change to diagnose image diffs in g3

Bug: skia:
Change-Id: I33226a0266093a98083b4c78cdaba402ce3f3929
Reviewed-on: https://skia-review.googlesource.com/19082
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
2 files changed