When creating testing backendTexture take colorspace into account.

Bug: skia:
Change-Id: Ifa8dbad3eca81790648476f9a6d3fa5a088fede9
Reviewed-on: https://skia-review.googlesource.com/122341
Reviewed-by: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
7 files changed