Revert of Switch wtf/SpinLock to std::atomic

Revert of Switch wtf/SpinLock to std::atomic (patchset #9 id:190001 of https://codereview.chromium.org/1463683002/ )

Reason for revert:
Tree is closed (Automatic: "compile" on http://build.chromium.org/p/chromium.memory/builders/Linux%20Chromium%20OS%20ASan%20LSan%20Builder/builds/19077 "Linux Chromium OS ASan LSan Builder" from 5e58730d6fe40ef7cead75954ef5b1c05dea6d4b : jschuh )

Original issue's description:
> Switch wtf/SpinLock to std::atomic
>
> Tsan identified a racy read in the existing spin lock loop.
> Tsan is correct in the absolute sense, even though the read is
> safe in practice. However, the architectures we support might
> change, or the behavior of the compiler might change, so the
> the best fix is to just use the proper std::atomic type,
> because that is guaranteed to always be safe. And the compiled
> code should be effectively unchanged.
>
> BUG=556469
> NOTRY=True
>
> Committed: https://crrev.com/5e58730d6fe40ef7cead75954ef5b1c05dea6d4b
> Cr-Commit-Position: refs/heads/master@{#363347}

TBR=esprehn@chromium.org,glider@chromium.org,haraken@chromium.org,yutak@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=556469
Committed: https://crrev.com/df707658fcdb00877c97b66bd473b9117ff57b15
Cr-Commit-Position: refs/heads/master@{#363348}

[jschuh, 2015-12-05 22:49:13]

Created Revert of Switch wtf/SpinLock to std::atomic

[commit-bot: I haz the power, 2015-12-05 22:49:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1502023002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1502023002/1

[commit-bot: I haz the power, 2015-12-05 22:50:44]

Description was changed from

==========
Revert of Switch wtf/SpinLock to std::atomic (patchset #9 id:190001 of
https://codereview.chromium.org/1463683002/ )

Reason for revert:
Tree is closed (Automatic: "compile" on
http://build.chromium.org/p/chromium.memory/builders/Linux%20Chromium%20OS%20...
"Linux Chromium OS ASan LSan Builder" from
5e58730d6fe40ef7cead75954ef5b1c05dea6d4b : jschuh )


Original issue's description:
> Switch wtf/SpinLock to std::atomic
> 
> Tsan identified a racy read in the existing spin lock loop.
> Tsan is correct in the absolute sense, even though the read is
> safe in practice. However, the architectures we support might
> change, or the behavior of the compiler might change, so the
> the best fix is to just use the proper std::atomic type,
> because that is guaranteed to always be safe. And the compiled
> code should be effectively unchanged.
> 
> BUG=556469
> NOTRY=True
> 
> Committed: https://crrev.com/5e58730d6fe40ef7cead75954ef5b1c05dea6d4b
> Cr-Commit-Position: refs/heads/master@{#363347}

TBR=esprehn@chromium.org,glider@chromium.org,haraken@chromium.org,yutak@chrom...
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=556469
==========

to

==========
Revert of Switch wtf/SpinLock to std::atomic (patchset #9 id:190001 of
https://codereview.chromium.org/1463683002/ )

Reason for revert:
Tree is closed (Automatic: "compile" on
http://build.chromium.org/p/chromium.memory/builders/Linux%20Chromium%20OS%20...
"Linux Chromium OS ASan LSan Builder" from
5e58730d6fe40ef7cead75954ef5b1c05dea6d4b : jschuh )


Original issue's description:
> Switch wtf/SpinLock to std::atomic
> 
> Tsan identified a racy read in the existing spin lock loop.
> Tsan is correct in the absolute sense, even though the read is
> safe in practice. However, the architectures we support might
> change, or the behavior of the compiler might change, so the
> the best fix is to just use the proper std::atomic type,
> because that is guaranteed to always be safe. And the compiled
> code should be effectively unchanged.
> 
> BUG=556469
> NOTRY=True
> 
> Committed: https://crrev.com/5e58730d6fe40ef7cead75954ef5b1c05dea6d4b
> Cr-Commit-Position: refs/heads/master@{#363347}

TBR=esprehn@chromium.org,glider@chromium.org,haraken@chromium.org,yutak@chrom...
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=556469
==========

[commit-bot: I haz the power, 2015-12-05 22:50:45]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-05 22:51:31]

Description was changed from

==========
Revert of Switch wtf/SpinLock to std::atomic (patchset #9 id:190001 of
https://codereview.chromium.org/1463683002/ )

Reason for revert:
Tree is closed (Automatic: "compile" on
http://build.chromium.org/p/chromium.memory/builders/Linux%20Chromium%20OS%20...
"Linux Chromium OS ASan LSan Builder" from
5e58730d6fe40ef7cead75954ef5b1c05dea6d4b : jschuh )


Original issue's description:
> Switch wtf/SpinLock to std::atomic
> 
> Tsan identified a racy read in the existing spin lock loop.
> Tsan is correct in the absolute sense, even though the read is
> safe in practice. However, the architectures we support might
> change, or the behavior of the compiler might change, so the
> the best fix is to just use the proper std::atomic type,
> because that is guaranteed to always be safe. And the compiled
> code should be effectively unchanged.
> 
> BUG=556469
> NOTRY=True
> 
> Committed: https://crrev.com/5e58730d6fe40ef7cead75954ef5b1c05dea6d4b
> Cr-Commit-Position: refs/heads/master@{#363347}

TBR=esprehn@chromium.org,glider@chromium.org,haraken@chromium.org,yutak@chrom...
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=556469
==========

to

==========
Revert of Switch wtf/SpinLock to std::atomic (patchset #9 id:190001 of
https://codereview.chromium.org/1463683002/ )

Reason for revert:
Tree is closed (Automatic: "compile" on
http://build.chromium.org/p/chromium.memory/builders/Linux%20Chromium%20OS%20...
"Linux Chromium OS ASan LSan Builder" from
5e58730d6fe40ef7cead75954ef5b1c05dea6d4b : jschuh )

Original issue's description:
> Switch wtf/SpinLock to std::atomic
>
> Tsan identified a racy read in the existing spin lock loop.
> Tsan is correct in the absolute sense, even though the read is
> safe in practice. However, the architectures we support might
> change, or the behavior of the compiler might change, so the
> the best fix is to just use the proper std::atomic type,
> because that is guaranteed to always be safe. And the compiled
> code should be effectively unchanged.
>
> BUG=556469
> NOTRY=True
>
> Committed: https://crrev.com/5e58730d6fe40ef7cead75954ef5b1c05dea6d4b
> Cr-Commit-Position: refs/heads/master@{#363347}

TBR=esprehn@chromium.org,glider@chromium.org,haraken@chromium.org,yutak@chrom...
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=556469

Committed: https://crrev.com/df707658fcdb00877c97b66bd473b9117ff57b15
Cr-Commit-Position: refs/heads/master@{#363348}
==========

[commit-bot: I haz the power, 2015-12-05 22:51:32]

Patchset 1 (id:??) landed as
https://crrev.com/df707658fcdb00877c97b66bd473b9117ff57b15
Cr-Commit-Position: refs/heads/master@{#363348}