Change SkRecord to use SkArenaAlloc

This CL uses the strategy of allocating raw bytes with the proper
alignment so that SkRecord can manage the object lifetimes.

Change-Id: I73604d41a3c6a12d1e2f7f8419f75b95c0190f68
Reviewed-on: https://skia-review.googlesource.com/13621
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
2 files changed