Cleanup SkImage YUV texture factories.

Remove unused GrBackendObject variants.

Add versions without redundant size param.

Make this work with GrBackendTextures that weren't created with a GrPixelConfig.

Change-Id: Ic1bbf5f2817cebab938b4f31000126a6ab5c44d5
Reviewed-on: https://skia-review.googlesource.com/114460
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
7 files changed