Revert of Port most uses of SkOnce to SkLazyPtr. (https://codereview.chromium.org/304383005/)

Reason for revert:
Leaking refs on SkTypeface on Macs.

Original issue's description:
> Port most uses of SkOnce to SkLazyPtr.
>
> BUG=skia:
>
> Committed: http://code.google.com/p/skia/source/detail?r=15006

R=reed@google.com, mtklein@chromium.org
TBR=mtklein@chromium.org, reed@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/304283007

git-svn-id: http://skia.googlecode.com/svn/trunk/include@15009 2bbb7eff-a529-9590-31e7-b0007b416f81