Let unbudgeted, unique keyed resources stay in gpu ResourceCache.

Also has some fixes to make sure we are allowing unique keys on uninstantiated
proxies and that we then forward those unique keys to resources during lazy
instantiation.

Bug: skia:
Change-Id: Ief33bc38dbe06a081123a86e33c69b239f5a862b
Reviewed-on: https://skia-review.googlesource.com/152980
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
5 files changed