Revert of SkOncePtr -> SkOnce

Revert of SkOncePtr -> SkOnce (patchset #4 id:60001 of https://codereview.chromium.org/1953533002/ )

Reason for revert:
broken the Mac and Linux builders, e.g.:

https://build.chromium.org/p/chromium/builders/Mac/builds/15151
https://build.chromium.org/p/chromium/builders/Linux%20x64/builds/19052

Original issue's description:
> SkOncePtr -> SkOnce
> 
> It's always nice to kill off a synchronization primitive.
> And while less terse, I think this new code reads more clearly.
> 
> ... and, SkOncePtr's tests were the only thing now using sk_num_cores()
> outside of SkTaskGroup, so I've hidden it as static inside SkTaskGroup.cpp.
> 
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1953533002
> CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
> 
> Committed: https://skia.googlesource.com/skia/+/9bd3fc7fa9bb7cad050bd619aa93d4c48ebb5c02

TBR=herb@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Committed: https://skia.googlesource.com/skia/+/7eb33da7eede34c050b865dbb1b60c3dcea7191b

[reed1, 2016-05-05 00:14:28]

Created Revert of SkOncePtr -> SkOnce

[commit-bot: I haz the power, 2016-05-05 00:14:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1945293004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1945293004/1

[commit-bot: I haz the power, 2016-05-05 00:14:46]

Description was changed from

==========
Revert of SkOncePtr -> SkOnce (patchset #4 id:60001 of
https://codereview.chromium.org/1953533002/ )

Reason for revert:
broken the Mac and Linux builders, e.g.:

https://build.chromium.org/p/chromium/builders/Mac/builds/15151
https://build.chromium.org/p/chromium/builders/Linux%20x64/builds/19052

Original issue's description:
> SkOncePtr -> SkOnce
> 
> It's always nice to kill off a synchronization primitive.
> And while less terse, I think this new code reads more clearly.
> 
> ... and, SkOncePtr's tests were the only thing now using sk_num_cores()
> outside of SkTaskGroup, so I've hidden it as static inside SkTaskGroup.cpp.
> 
> BUG=skia:
> GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
>
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
> 
> Committed:
https://skia.googlesource.com/skia/+/9bd3fc7fa9bb7cad050bd619aa93d4c48ebb5c02

TBR=herb@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:
==========

to

==========
Revert of SkOncePtr -> SkOnce (patchset #4 id:60001 of
https://codereview.chromium.org/1953533002/ )

Reason for revert:
broken the Mac and Linux builders, e.g.:

https://build.chromium.org/p/chromium/builders/Mac/builds/15151
https://build.chromium.org/p/chromium/builders/Linux%20x64/builds/19052

Original issue's description:
> SkOncePtr -> SkOnce
> 
> It's always nice to kill off a synchronization primitive.
> And while less terse, I think this new code reads more clearly.
> 
> ... and, SkOncePtr's tests were the only thing now using sk_num_cores()
> outside of SkTaskGroup, so I've hidden it as static inside SkTaskGroup.cpp.
> 
> BUG=skia:
> GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
>
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
> 
> Committed:
https://skia.googlesource.com/skia/+/9bd3fc7fa9bb7cad050bd619aa93d4c48ebb5c02

TBR=herb@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Committed:
https://skia.googlesource.com/skia/+/7eb33da7eede34c050b865dbb1b60c3dcea7191b
==========

[commit-bot: I haz the power, 2016-05-05 00:14:47]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/7eb33da7eede34c050b865dbb1b60c3dcea7191b

[sclittle, 2016-05-05 00:51:59]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1952133002/ by sclittle@chromium.org.

The reason for reverting is: The original CL was accidentally reverted instead
of https://codereview.chromium.org/1945343003/, so I'm relanding the original
CL..

[reed1, 2016-05-05 08:28:41]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1949313003/ by reed@google.com.

The reason for reverting is: previous revert unneeded (I think).