Rename SkTArray::allocCntForTest to capacity.

A change made in the spirit of not being weird. C++ containers typically
expose their capacities to non-test code, with a function "capacity."

Change-Id: Icc7e175a20aff53ef9e144ac9620ced29ef5e95a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/325657
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2 files changed