Split SkTRacy into SkTRacy and SkTRacyReffable.

Split SkTRacy into SkTRacy and SkTRacyReffable.

Looks like TSAN can't always suppress our existing implementation of SkTRacy
(what is turning here into SkTRacyReffable).  To minimize flakiness, use
SkTRacy where possible and SkTRacyReffable where necessary.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/497cda3a6b72b9cb390334e8756d38b4ffac044f

NOTRY=true

Committed: https://skia.googlesource.com/skia/+/42483d902634f6bfc65dbd8bc999610faf372ef0

[mtklein, 2014-07-10 15:55:16]

Not sure how best to do the forced-caching yet, so let's land the soft- and
hard- solution we talked about in the meanwhile.

[robertphillips, 2014-07-10 15:59:44]

lgtm

[mtklein, 2014-07-10 16:03:38]

+reed for include/

[reed1, 2014-07-10 17:20:41]

lgtm

[mtklein, 2014-07-10 17:21:15]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2014-07-10 17:22:21]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/mtklein@chromium.org/388503002/1

[commit-bot: I haz the power, 2014-07-10 17:38:30]

Change committed as 497cda3a6b72b9cb390334e8756d38b4ffac044f

[mtklein, 2014-07-10 17:51:23]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2014-07-10 17:52:40]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/mtklein@chromium.org/388503002/20001

[mtklein, 2014-07-10 18:11:39]

The CQ bit was unchecked by mtklein@google.com

[mtklein, 2014-07-10 18:11:39]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2014-07-10 18:11:46]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/mtklein@chromium.org/388503002/20001

[commit-bot: I haz the power, 2014-07-10 18:12:03]

Change committed as 42483d902634f6bfc65dbd8bc999610faf372ef0