Reland of Delete rtc::linked_ptr.

Reland of Delete rtc::linked_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2579753002/ )

Only use, in statstypes.h, replaced by rtc::scoped_refptr.

Reason for revert:
Intend to switch from unique_ptr to scoped_refptr,
and then reland.

Original issue's description:
> Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2581663002/ )
> 
> Reason for revert:
> This change broke Chrome too. It's stats processing wants to make a copy of webrtc's stats mapping, which is no longer possible with std::unique_ptr.
> 
> Original issue's description:
> > Reland of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2576673002/ )
> >
> > Reason for revert:
> > Downstream project fixed to not make copies while iterating over the stats mapping.
> >
> > Original issue's description:
> > > Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2567143003/ )
> > >
> > > Reason for revert:
> > > The change from rtc::linked_ptr to std::unique_ptr broke a downstream project.
> > >
> > > Original issue's description:
> > > > Delete rtc::linked_ptr. Only use, in statstypes.h, replaced with std::unique_ptr.
> > > >
> > > > BUG=webrtc:6424
> > > >
> > > > Committed: https://crrev.com/36f74e55792cae19db8b222c29aa38d6e0eb1225
> > > > Cr-Commit-Position: refs/heads/master@{#15588}
> > >
> > > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > > # Skipping CQ checks because original CL landed less than 1 days ago.
> > > NOPRESUBMIT=true
> > > NOTREECHECKS=true
> > > NOTRY=true
> > > BUG=webrtc:6424
> > >
> > > Committed: https://crrev.com/8afbc8cba65d99bb7a0feece8fb3055b144106b1
> > > Cr-Commit-Position: refs/heads/master@{#15589}
> >
> > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > # Not skipping CQ checks because original CL landed more than 1 days ago.
> > BUG=webrtc:6424
> >
> > Committed: https://crrev.com/06035cf53abad80b0525f286a3b81e388cc7ee00
> > Cr-Commit-Position: refs/heads/master@{#15627}
> 
> TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6424
> 
> Committed: https://crrev.com/6a58f33450a46370039cd82537612040a91165b3
> Cr-Commit-Position: refs/heads/master@{#15629}

TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6424
Review-Url: https://codereview.webrtc.org/2641793002
Cr-Commit-Position: refs/heads/master@{#16148}
Committed: https://chromium.googlesource.com/external/webrtc/+/6da303db1d25a980b1b835d2b6936ca2e5eddc06

[nisse-webrtc, 2017-01-18 09:21:45]

Created Reland of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr.

[the sun, 2017-01-18 10:00:55]

lgtm

[nisse-webrtc, 2017-01-18 10:46:00]

Description was changed from

==========
Reland of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2579753002/
)

Reason for revert:
Intend to switch from unique_ptr to scoped_refptr,
and then reland.

Original issue's description:
> Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2581663002/
)
> 
> Reason for revert:
> This change broke Chrome too. It's stats processing wants to make a copy of
webrtc's stats mapping, which is no longer possible with std::unique_ptr.
> 
> Original issue's description:
> > Reland of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2576673002/
)
> >
> > Reason for revert:
> > Downstream project fixed to not make copies while iterating over the stats
mapping.
> >
> > Original issue's description:
> > > Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2567143003/
)
> > >
> > > Reason for revert:
> > > The change from rtc::linked_ptr to std::unique_ptr broke a downstream
project.
> > >
> > > Original issue's description:
> > > > Delete rtc::linked_ptr. Only use, in statstypes.h, replaced with
std::unique_ptr.
> > > >
> > > > BUG=webrtc:6424
> > > >
> > > > Committed: https://crrev.com/36f74e55792cae19db8b222c29aa38d6e0eb1225
> > > > Cr-Commit-Position: refs/heads/master@{#15588}
> > >
> > > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > > # Skipping CQ checks because original CL landed less than 1 days ago.
> > > NOPRESUBMIT=true
> > > NOTREECHECKS=true
> > > NOTRY=true
> > > BUG=webrtc:6424
> > >
> > > Committed: https://crrev.com/8afbc8cba65d99bb7a0feece8fb3055b144106b1
> > > Cr-Commit-Position: refs/heads/master@{#15589}
> >
> > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > # Not skipping CQ checks because original CL landed more than 1 days ago.
> > BUG=webrtc:6424
> >
> > Committed: https://crrev.com/06035cf53abad80b0525f286a3b81e388cc7ee00
> > Cr-Commit-Position: refs/heads/master@{#15627}
> 
> TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6424
> 
> Committed: https://crrev.com/6a58f33450a46370039cd82537612040a91165b3
> Cr-Commit-Position: refs/heads/master@{#15629}

TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6424
==========

to

==========
Reland of Delete rtc::linked_ptr. (patchset #1 id:1 of
https://codereview.webrtc.org/2579753002/ )

Only use, in statstypes.h, replaced by rtc::scoped_refptr.

Reason for revert:
Intend to switch from unique_ptr to scoped_refptr,
and then reland.

Original issue's description:
> Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2581663002/
)
> 
> Reason for revert:
> This change broke Chrome too. It's stats processing wants to make a copy of
webrtc's stats mapping, which is no longer possible with std::unique_ptr.
> 
> Original issue's description:
> > Reland of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2576673002/
)
> >
> > Reason for revert:
> > Downstream project fixed to not make copies while iterating over the stats
mapping.
> >
> > Original issue's description:
> > > Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2567143003/
)
> > >
> > > Reason for revert:
> > > The change from rtc::linked_ptr to std::unique_ptr broke a downstream
project.
> > >
> > > Original issue's description:
> > > > Delete rtc::linked_ptr. Only use, in statstypes.h, replaced with
std::unique_ptr.
> > > >
> > > > BUG=webrtc:6424
> > > >
> > > > Committed: https://crrev.com/36f74e55792cae19db8b222c29aa38d6e0eb1225
> > > > Cr-Commit-Position: refs/heads/master@{#15588}
> > >
> > > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > > # Skipping CQ checks because original CL landed less than 1 days ago.
> > > NOPRESUBMIT=true
> > > NOTREECHECKS=true
> > > NOTRY=true
> > > BUG=webrtc:6424
> > >
> > > Committed: https://crrev.com/8afbc8cba65d99bb7a0feece8fb3055b144106b1
> > > Cr-Commit-Position: refs/heads/master@{#15589}
> >
> > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > # Not skipping CQ checks because original CL landed more than 1 days ago.
> > BUG=webrtc:6424
> >
> > Committed: https://crrev.com/06035cf53abad80b0525f286a3b81e388cc7ee00
> > Cr-Commit-Position: refs/heads/master@{#15627}
> 
> TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6424
> 
> Committed: https://crrev.com/6a58f33450a46370039cd82537612040a91165b3
> Cr-Commit-Position: refs/heads/master@{#15629}

TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6424
==========

[nisse-webrtc, 2017-01-18 10:54:01]

I think I've found the problem.

https://codereview.webrtc.org/2641793002/diff/150001/webrtc/api/statstypes.h
File webrtc/api/statstypes.h (right):

https://codereview.webrtc.org/2641793002/diff/150001/webrtc/api/statstypes.h#...
webrtc/api/statstypes.h:316: mutable int ref_count_;
It seems I forgot to initialize this one... Will fix.

[nisse-webrtc, 2017-01-18 11:34:08]

The CQ bit was checked by nisse@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-18 11:34:14]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[tommi, 2017-01-18 11:59:22]

tommi@webrtc.org changed reviewers:
+ tommi@webrtc.org

[tommi, 2017-01-18 11:59:22]

https://codereview.webrtc.org/2641793002/diff/170001/webrtc/api/statstypes.h
File webrtc/api/statstypes.h (right):

https://codereview.webrtc.org/2641793002/diff/170001/webrtc/api/statstypes.h#...
webrtc/api/statstypes.h:269: // the Values mapping) must occur on webrtc's
signalling thread.
can we use a thread or sequence checker in DCHECK enabled builds?

[nisse-webrtc, 2017-01-18 12:16:32]

https://codereview.webrtc.org/2641793002/diff/170001/webrtc/api/statstypes.h
File webrtc/api/statstypes.h (right):

https://codereview.webrtc.org/2641793002/diff/170001/webrtc/api/statstypes.h#...
webrtc/api/statstypes.h:269: // the Values mapping) must occur on webrtc's
signalling thread.
On 2017/01/18 11:59:22, tommi (webrtc) wrote:
> can we use a thread or sequence checker in DCHECK enabled builds?

Sure, adding a ThreadChecker should be possible. And use it in AddRef and
Release. Do you want me to do that?

[tommi, 2017-01-18 12:18:49]

On 2017/01/18 12:16:32, nisse-webrtc wrote:
> https://codereview.webrtc.org/2641793002/diff/170001/webrtc/api/statstypes.h
> File webrtc/api/statstypes.h (right):
> 
>
https://codereview.webrtc.org/2641793002/diff/170001/webrtc/api/statstypes.h#...
> webrtc/api/statstypes.h:269: // the Values mapping) must occur on webrtc's
> signalling thread.
> On 2017/01/18 11:59:22, tommi (webrtc) wrote:
> > can we use a thread or sequence checker in DCHECK enabled builds?
> 
> Sure, adding a ThreadChecker should be possible. And use it in AddRef and
> Release. Do you want me to do that?

yes please

[nisse-webrtc, 2017-01-18 12:33:21]

On 2017/01/18 12:18:49, tommi (webrtc) wrote:
> On 2017/01/18 12:16:32, nisse-webrtc wrote:
> > https://codereview.webrtc.org/2641793002/diff/170001/webrtc/api/statstypes.h
> > File webrtc/api/statstypes.h (right):
> > 
> >
>
https://codereview.webrtc.org/2641793002/diff/170001/webrtc/api/statstypes.h#...
> > webrtc/api/statstypes.h:269: // the Values mapping) must occur on webrtc's
> > signalling thread.
> > On 2017/01/18 11:59:22, tommi (webrtc) wrote:
> > > can we use a thread or sequence checker in DCHECK enabled builds?
> > 
> > Sure, adding a ThreadChecker should be possible. And use it in AddRef and
> > Release. Do you want me to do that?
> 
> yes please

Done.

[tommi, 2017-01-18 12:48:20]

lgtm

https://codereview.webrtc.org/2641793002/diff/190001/webrtc/api/statstypes.h
File webrtc/api/statstypes.h (right):

https://codereview.webrtc.org/2641793002/diff/190001/webrtc/api/statstypes.h#...
webrtc/api/statstypes.h:322: rtc::ThreadChecker thread_checker_;
just fyi, SequenceChecker is also an option and perhaps a better one for future
compatibility.

[nisse-webrtc, 2017-01-18 12:56:22]

https://codereview.webrtc.org/2641793002/diff/190001/webrtc/api/statstypes.h
File webrtc/api/statstypes.h (right):

https://codereview.webrtc.org/2641793002/diff/190001/webrtc/api/statstypes.h#...
webrtc/api/statstypes.h:322: rtc::ThreadChecker thread_checker_;
On 2017/01/18 12:48:20, tommi (webrtc) wrote:
> just fyi, SequenceChecker is also an option and perhaps a better one for
future
> compatibility.

Seems a bit tricky to convert this code to use a TaskQueue. The callback to
OnComplete would then be a task, and Chrome would have to post a new task on the
same task queue to delete its copy.

[nisse-webrtc, 2017-01-18 12:57:26]

The CQ bit was checked by nisse@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-18 12:57:36]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2017-01-18 14:06:19]

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

[commit-bot: I haz the power, 2017-01-18 14:06:19]

Dry run: This issue passed the CQ dry run.

[nisse-webrtc, 2017-01-18 14:08:34]

The CQ bit was checked by nisse@webrtc.org

[nisse-webrtc, 2017-01-18 14:08:35]

The patchset sent to the CQ was uploaded after l-g-t-m from solenberg@webrtc.org
Link to the patchset: https://codereview.webrtc.org/2641793002/#ps190001 (title:
"Add a ThreadChecker to StatsReport::Value.")

[commit-bot: I haz the power, 2017-01-18 14:08:39]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2017-01-18 14:10:54]

CQ is committing da patch.

Bot data: {"patchset_id": 190001, "attempt_start_ts": 1484748514837300,
"parent_rev": "1b3ce86d53427543f23d2258cb7cb78f286d34a2", "commit_rev":
"6da303db1d25a980b1b835d2b6936ca2e5eddc06"}

[commit-bot: I haz the power, 2017-01-18 14:10:57]

Description was changed from

==========
Reland of Delete rtc::linked_ptr. (patchset #1 id:1 of
https://codereview.webrtc.org/2579753002/ )

Only use, in statstypes.h, replaced by rtc::scoped_refptr.

Reason for revert:
Intend to switch from unique_ptr to scoped_refptr,
and then reland.

Original issue's description:
> Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2581663002/
)
> 
> Reason for revert:
> This change broke Chrome too. It's stats processing wants to make a copy of
webrtc's stats mapping, which is no longer possible with std::unique_ptr.
> 
> Original issue's description:
> > Reland of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2576673002/
)
> >
> > Reason for revert:
> > Downstream project fixed to not make copies while iterating over the stats
mapping.
> >
> > Original issue's description:
> > > Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2567143003/
)
> > >
> > > Reason for revert:
> > > The change from rtc::linked_ptr to std::unique_ptr broke a downstream
project.
> > >
> > > Original issue's description:
> > > > Delete rtc::linked_ptr. Only use, in statstypes.h, replaced with
std::unique_ptr.
> > > >
> > > > BUG=webrtc:6424
> > > >
> > > > Committed: https://crrev.com/36f74e55792cae19db8b222c29aa38d6e0eb1225
> > > > Cr-Commit-Position: refs/heads/master@{#15588}
> > >
> > > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > > # Skipping CQ checks because original CL landed less than 1 days ago.
> > > NOPRESUBMIT=true
> > > NOTREECHECKS=true
> > > NOTRY=true
> > > BUG=webrtc:6424
> > >
> > > Committed: https://crrev.com/8afbc8cba65d99bb7a0feece8fb3055b144106b1
> > > Cr-Commit-Position: refs/heads/master@{#15589}
> >
> > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > # Not skipping CQ checks because original CL landed more than 1 days ago.
> > BUG=webrtc:6424
> >
> > Committed: https://crrev.com/06035cf53abad80b0525f286a3b81e388cc7ee00
> > Cr-Commit-Position: refs/heads/master@{#15627}
> 
> TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6424
> 
> Committed: https://crrev.com/6a58f33450a46370039cd82537612040a91165b3
> Cr-Commit-Position: refs/heads/master@{#15629}

TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6424
==========

to

==========
Reland of Delete rtc::linked_ptr. (patchset #1 id:1 of
https://codereview.webrtc.org/2579753002/ )

Only use, in statstypes.h, replaced by rtc::scoped_refptr.

Reason for revert:
Intend to switch from unique_ptr to scoped_refptr,
and then reland.

Original issue's description:
> Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2581663002/
)
> 
> Reason for revert:
> This change broke Chrome too. It's stats processing wants to make a copy of
webrtc's stats mapping, which is no longer possible with std::unique_ptr.
> 
> Original issue's description:
> > Reland of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2576673002/
)
> >
> > Reason for revert:
> > Downstream project fixed to not make copies while iterating over the stats
mapping.
> >
> > Original issue's description:
> > > Revert of Delete rtc::linked_ptr. Only use, in statstypes.h, replaced bu
std::unique_ptr. (patchset #1 id:1 of https://codereview.webrtc.org/2567143003/
)
> > >
> > > Reason for revert:
> > > The change from rtc::linked_ptr to std::unique_ptr broke a downstream
project.
> > >
> > > Original issue's description:
> > > > Delete rtc::linked_ptr. Only use, in statstypes.h, replaced with
std::unique_ptr.
> > > >
> > > > BUG=webrtc:6424
> > > >
> > > > Committed: https://crrev.com/36f74e55792cae19db8b222c29aa38d6e0eb1225
> > > > Cr-Commit-Position: refs/heads/master@{#15588}
> > >
> > > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > > # Skipping CQ checks because original CL landed less than 1 days ago.
> > > NOPRESUBMIT=true
> > > NOTREECHECKS=true
> > > NOTRY=true
> > > BUG=webrtc:6424
> > >
> > > Committed: https://crrev.com/8afbc8cba65d99bb7a0feece8fb3055b144106b1
> > > Cr-Commit-Position: refs/heads/master@{#15589}
> >
> > TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> > # Not skipping CQ checks because original CL landed more than 1 days ago.
> > BUG=webrtc:6424
> >
> > Committed: https://crrev.com/06035cf53abad80b0525f286a3b81e388cc7ee00
> > Cr-Commit-Position: refs/heads/master@{#15627}
> 
> TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6424
> 
> Committed: https://crrev.com/6a58f33450a46370039cd82537612040a91165b3
> Cr-Commit-Position: refs/heads/master@{#15629}

TBR=solenberg@webrtc.org,pthatcher@webrtc.org,hta@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6424

Review-Url: https://codereview.webrtc.org/2641793002
Cr-Commit-Position: refs/heads/master@{#16148}
Committed:
https://chromium.googlesource.com/external/webrtc/+/6da303db1d25a980b1b835d2b...
==========

[commit-bot: I haz the power, 2017-01-18 14:10:58]

Committed patchset #5 (id:190001) as
https://chromium.googlesource.com/external/webrtc/+/6da303db1d25a980b1b835d2b...