Add GrResourceAllocator::reset

This is used in the fallback code when reordering produces
a DAG that goes over our memory budget.

Bug: skia:10877
Change-Id: I13772b30e270eb546957b88586ded1cf42d2dbeb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/397136
Commit-Queue: Adlai Holler <adlai@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
4 files changed