Make SkTArray maintain reserve count

Bug: skia:6690
Change-Id: I01f5bb56c654f513365d6ce9f19712d9be07a08d
Reviewed-on: https://skia-review.googlesource.com/20055
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Yuqian Li <liyuqian@google.com>
2 files changed