Revert "Revert "Use SkImage to manage mip map cache purging, not Bitmap/PixelRef""

This reverts commit f7ddaa8a1bb305b679632c5b52e3a9e0f9be987a.

Bug: skia:
Change-Id: Idc0459e119cefbf580aea1f27dda9836d16bb293
Reviewed-on: https://skia-review.googlesource.com/c/162039
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
6 files changed