Fix height calculation when doing copyImageToBuffer

The bug only manifested when we were forcing copies from the origin.

Bug: skia:
Change-Id: I63f17ad9282b10f0d9c9c9ef38031faad32e20a3
Reviewed-on: https://skia-review.googlesource.com/110445
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
1 file changed