Update CrossContext Image test to fix memory leak

Bug: skia:
Change-Id: I8c0abf16d5eb366cdc5296f8df9f33cc0e8f4cc4
Reviewed-on: https://skia-review.googlesource.com/26662
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
1 file changed