Work around un-safe downcast in PromiseLazyInstantiateCallback destructor after a context abandon

90% of this CL is just renaming. The only two substantive changes are:
   holding a GrTexture* (rather than a GrGpuResource*) in the GrTextureFreedMessage (this avoids the downcast)
   adding the abandoned() checks to the two GrContext::purgeUnlockedResources methods (this prevents accesses of the message queue)

Bug: 1011368, 1014993
Change-Id: Ifff3842f7802add6b7cd34595578369543698ba1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/249001
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
6 files changed