Bring back SkImage::makeTextureImage

Bring back SkImage::makeTextureImage

Ensures that an image is GPU backed on the passed-in GrContxt. The new
version requires a destination color space (intended usage of the image),
so we can make a proper decision about decoded format.

This reverts commit d263413a2a92cafe3fd3b051c67d00206c9a0e4d.

BUG=skia:

Change-Id: Ibccddbafc301779559592045ed5a5fa9264e7432
Reviewed-on: https://skia-review.googlesource.com/8116
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>