Revert of remove Sk64 from public API, and start to remove usage internally

Revert of https://codereview.chromium.org/113823003/
Reason for revert: need to update callsites in linux codecs

TBR=robertphillips@google.com
NOTREECHECKS=true
NOTRY=true
BUG=

Committed: http://code.google.com/p/skia/source/detail?r=12841

[reed1, 2013-12-30 14:24:18]

Created Revert of remove Sk64 from public API, and start to remove usage
internally

[commit-bot: I haz the power, 2013-12-30 14:24:23]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/reed@google.com/122283002/1

[commit-bot: I haz the power, 2013-12-30 14:24:42]

Change committed as 12841