When creating emptyp MipMap proxies, don't instantiate them immediately. Attempt 3

original: https://skia-review.googlesource.com/106966

Bug: skia:
Change-Id: I779985cef2d3c4f36a0129d8ecedd12e510bec7e
Reviewed-on: https://skia-review.googlesource.com/107781
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
9 files changed