Rename opPODAllocator to recordTimeAllocator

Hopefully this is a better name. "POD" is no longer accurate since we are storing GrPipeline's in this arena.

Bug: skia:9455
Change-Id: I610267633088b0af4f0cbb36f479bf5eb6c6d0cb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/254992
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
7 files changed