Make experimental Perlin noise shader take texture proxies

This is split out of: https://skia-review.googlesource.com/c/8823/ (Remove GrFragmentProcessor-derived class' GrTexture-based ctors)

Change-Id: I18c444981f5c72e9688866e045c90844bc4945b1
Reviewed-on: https://skia-review.googlesource.com/9917
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
3 files changed