Revert "Fix reset and deleting behavior."

Revert "Fix reset and deleting behavior."

This reverts commit 412a86d014783be99a7a9a0fae407791b95806e8.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Fix reset and deleting behavior.
>
> * Reset the Arena state.
> * Call all the dtors before deleting the blocks.
>
> TBR=mtklein@google.com
>
> Change-Id: Iac320fec16e572cc9a6184c1f580089ab720f036
> Reviewed-on: https://skia-review.googlesource.com/7221
> Reviewed-by: Herb Derby <herb@google.com>
> Commit-Queue: Herb Derby <herb@google.com>
>

TBR=herb@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I4f4d34e0190a60d418f11326a9a9688d7487b8d8
Reviewed-on: https://skia-review.googlesource.com/7261
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Herb Derby <herb@google.com>