In SkCanvas destructor, discard (rather than blit) unbalanced layers

Bug: skia:12267
Change-Id: I6808f62b2385a3466b1a93db905041a6529f58cb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/433360
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Florin Malita <fmalita@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Mike Reed <reed@google.com>
2 files changed