Remove SkImage_Base::peekTexture call

Change-Id: Ie5b6bec8df083e0a128aa234d80f5a214cd98f0d
Reviewed-on: https://skia-review.googlesource.com/20741
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
6 files changed