Revert of Create libsampler as V8 sampler library.

Revert of Create libsampler as V8 sampler library. (patchset #24 id:460001 of https://codereview.chromium.org/1922303002/ )

Reason for revert:
V8 Linux64 TSAN failure because ThreadSanitizer indicated data race.

Original issue's description:
> Create libsampler as V8 sampler library.
>
> This patch does five things:
>
> 1. Extracts sampler as libsampler to provide sampling functionality support.
> 2. Makes SampleStack virtual so embedders can override the behaviour of sample collecting.
> 3. Removes sampler.[h|cc].
> 4. Moves sampling thread into log.cc as workaround to keep the --prof functionality.
> 5. Creates SamplerManager to manage the relationship between samplers and threads.
>
> The reason we port hashmap.h is that in debug mode, STL containers are using
> mutexes from a mutex pool, which may lead to deadlock when using asynchronously
> signal handler.
>
> Currently libsampler is used in V8 temporarily.
>
> BUG=v8:4789
> LOG=n
>
> Committed: https://crrev.com/06cc9b7c176a6223971deaa9fbcafe1a05058c7b
> Cr-Commit-Position: refs/heads/master@{#36527}

TBR=jochen@chromium.org,alph@chromium.org,fmeawad@chromium.org,yangguo@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4789
Committed: https://crrev.com/636f1e8e591dde3d71c45740ceda95ceb592cb0e
Cr-Commit-Position: refs/heads/master@{#36529}

[lpy, 2016-05-25 20:19:45]

Created Revert of Create libsampler as V8 sampler library.

[commit-bot: I haz the power, 2016-05-25 20:19:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2000323007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2000323007/1

[commit-bot: I haz the power, 2016-05-25 20:19:57]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-05-25 20:19:58]

No L-G-T-M from a valid reviewer yet. 
CQ run can only be started by full committers or once the patch has
received an L-G-T-M from a full committer.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
Committers are members of the group "project-v8-committers".
Note that this has nothing to do with OWNERS files.

[adamk, 2016-05-25 20:22:20]

adamk@chromium.org changed reviewers:
+ adamk@chromium.org

[adamk, 2016-05-25 20:22:20]

The CQ bit was checked by adamk@chromium.org

[adamk, 2016-05-25 20:22:20]

lgtm

[commit-bot: I haz the power, 2016-05-25 20:22:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2000323007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2000323007/1

[commit-bot: I haz the power, 2016-05-25 20:22:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-25 20:23:48]

Description was changed from

==========
Revert of Create libsampler as V8 sampler library. (patchset #24 id:460001 of
https://codereview.chromium.org/1922303002/ )

Reason for revert:
V8 Linux64 TSAN failure because ThreadSanitizer indicated data race.

Original issue's description:
> Create libsampler as V8 sampler library.
> 
> This patch does five things:
> 
> 1. Extracts sampler as libsampler to provide sampling functionality support.
> 2. Makes SampleStack virtual so embedders can override the behaviour of sample
collecting.
> 3. Removes sampler.[h|cc].
> 4. Moves sampling thread into log.cc as workaround to keep the --prof
functionality.
> 5. Creates SamplerManager to manage the relationship between samplers and
threads.
> 
> The reason we port hashmap.h is that in debug mode, STL containers are using
> mutexes from a mutex pool, which may lead to deadlock when using
asynchronously
> signal handler.
> 
> Currently libsampler is used in V8 temporarily.
> 
> BUG=v8:4789
> LOG=n
> 
> Committed: https://crrev.com/06cc9b7c176a6223971deaa9fbcafe1a05058c7b
> Cr-Commit-Position: refs/heads/master@{#36527}

TBR=jochen@chromium.org,alph@chromium.org,fmeawad@chromium.org,yangguo@chromi...
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4789
==========

to

==========
Revert of Create libsampler as V8 sampler library. (patchset #24 id:460001 of
https://codereview.chromium.org/1922303002/ )

Reason for revert:
V8 Linux64 TSAN failure because ThreadSanitizer indicated data race.

Original issue's description:
> Create libsampler as V8 sampler library.
>
> This patch does five things:
>
> 1. Extracts sampler as libsampler to provide sampling functionality support.
> 2. Makes SampleStack virtual so embedders can override the behaviour of sample
collecting.
> 3. Removes sampler.[h|cc].
> 4. Moves sampling thread into log.cc as workaround to keep the --prof
functionality.
> 5. Creates SamplerManager to manage the relationship between samplers and
threads.
>
> The reason we port hashmap.h is that in debug mode, STL containers are using
> mutexes from a mutex pool, which may lead to deadlock when using
asynchronously
> signal handler.
>
> Currently libsampler is used in V8 temporarily.
>
> BUG=v8:4789
> LOG=n
>
> Committed: https://crrev.com/06cc9b7c176a6223971deaa9fbcafe1a05058c7b
> Cr-Commit-Position: refs/heads/master@{#36527}

TBR=jochen@chromium.org,alph@chromium.org,fmeawad@chromium.org,yangguo@chromi...
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4789

Committed: https://crrev.com/636f1e8e591dde3d71c45740ceda95ceb592cb0e
Cr-Commit-Position: refs/heads/master@{#36529}
==========

[commit-bot: I haz the power, 2016-05-25 20:23:49]

Patchset 1 (id:??) landed as
https://crrev.com/636f1e8e591dde3d71c45740ceda95ceb592cb0e
Cr-Commit-Position: refs/heads/master@{#36529}