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}
6da303db1d