When clearing due to SkCodecAnimation::RestoreBGColor_DisposalMethod,
intersect the frameRect with the image size to prevent clearing outside
the bounds of the allocated memory.
Add a test image, created by the fuzzer.
BUG=skia:6046
Change-Id: I43676d28f82abf093ef801752f3a9e881580924c
Reviewed-on: https://skia-review.googlesource.com/5860
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Matt Sarett <msarett@google.com>
