Since Ganesh no longer will allocate mips late, this gives the clients a
way to tell skia that they want the texture they will be using to have mips.
It also supports allowing a client to take a non mipped texture backed
image and turn it into a new image which is mipped and texture backed.
Bug: chromium:834837
Change-Id: I1781ce618c22023b6309f248e7ee49e69bd3c6df
Reviewed-on: https://skia-review.googlesource.com/134323
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Eric Karl <ericrk@chromium.org>
Reviewed-by: Cary Clark <caryclark@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
5f4b09d523