libsampler: Cleanup SamplerManager

libsampler: Cleanup SamplerManager

  - Move the samplers related part out of SignalHandler class (remove friendship).
  - Make the SamplerManager class a singleton.
  - Minor tweaks.

BUG=v8:4789
Committed: https://crrev.com/8b47179b14bb4ed64ceac275584f65fec704bda7
Cr-Commit-Position: refs/heads/master@{#36596}

[alph, 2016-05-26 22:49:51]

The CQ bit was checked by alph@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-05-26 22:49:59]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2018773002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2018773002/1

[commit-bot: I haz the power, 2016-05-26 23:19:55]

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

[commit-bot: I haz the power, 2016-05-26 23:19:56]

Dry run: This issue passed the CQ dry run.

[commit-bot: I haz the power, 2016-05-26 23:20:04]

Dry run: None

[alph, 2016-05-26 23:22:26]

alph@chromium.org changed reviewers:
+ jochen@chromium.org, lpy@chromium.org, yangguo@chromium.org

[alph, 2016-05-26 23:22:27]

Yang, could you please take a look.

[lpy, 2016-05-27 05:47:37]

lgtm

[Yang, 2016-05-30 13:06:53]

On 2016/05/27 05:47:37, lpy wrote:
> lgtm

lgtm.

[alph, 2016-05-30 15:51:14]

The CQ bit was checked by alph@chromium.org

[commit-bot: I haz the power, 2016-05-30 15:51:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2018773002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2018773002/1

[commit-bot: I haz the power, 2016-05-30 16:19:15]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-30 16:21:47]

Description was changed from

==========
libsampler: Cleanup SamplerManager

  - Move the samplers related part out of SignalHandler class (remove
friendship).
  - Make the SamplerManager class a singleton.
  - Minor tweaks.

BUG=v8:4789
==========

to

==========
libsampler: Cleanup SamplerManager

  - Move the samplers related part out of SignalHandler class (remove
friendship).
  - Make the SamplerManager class a singleton.
  - Minor tweaks.

BUG=v8:4789

Committed: https://crrev.com/8b47179b14bb4ed64ceac275584f65fec704bda7
Cr-Commit-Position: refs/heads/master@{#36596}
==========

[commit-bot: I haz the power, 2016-05-30 16:21:49]

Patchset 1 (id:??) landed as
https://crrev.com/8b47179b14bb4ed64ceac275584f65fec704bda7
Cr-Commit-Position: refs/heads/master@{#36596}