Remove references between RTCPeerConnection and RTCDataChannel.

The underlying WebRTC objects maintain all the needed references.
No references are actually needed in the blink layer.

BUG=564965
Committed: https://crrev.com/0004ce15cdf065966508c61a5265ae8662e363ed
Cr-Commit-Position: refs/heads/master@{#371667}

[Guido Urdaneta, 2016-01-26 18:08:52]

Description was changed from

==========
Make the RTCPeerConnection reference in RTCDataChannel strong.

Also remove RTCDataChannel references from RTCPeerConnection.


BUG=564965
==========

to

==========
Make the RTCPeerConnection reference in RTCDataChannel strong.

Also remove RTCDataChannel references from RTCPeerConnection.


BUG=564965
==========

[Guido Urdaneta, 2016-01-26 18:08:53]

guidou@chromium.org changed reviewers:
+ tommi@chromium.org

[Guido Urdaneta, 2016-01-26 18:13:17]

Hi, PTAL.

See bug for a discussion about this change.

[Guido Urdaneta, 2016-01-26 19:50:57]

Description was changed from

==========
Make the RTCPeerConnection reference in RTCDataChannel strong.

Also remove RTCDataChannel references from RTCPeerConnection.


BUG=564965
==========

to

==========
The underlying WebRTC objects keep have all needed references.
No references are actually needed in the blink layer.

BUG=564965
==========

[Guido Urdaneta, 2016-01-26 20:07:57]

Description was changed from

==========
The underlying WebRTC objects keep have all needed references.
No references are actually needed in the blink layer.

BUG=564965
==========

to

==========
The underlying WebRTC objects maintain all the needed references.
No references are actually needed in the blink layer.

BUG=564965
==========

[tommi (sloooow) - chröme, 2016-01-26 23:15:57]

The CQ bit was checked by tommi@chromium.org

[tommi (sloooow) - chröme, 2016-01-26 23:15:58]

lgtm

[commit-bot: I haz the power, 2016-01-26 23:18:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1634073003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1634073003/40001

[commit-bot: I haz the power, 2016-01-27 01:08:30]

Description was changed from

==========
The underlying WebRTC objects maintain all the needed references.
No references are actually needed in the blink layer.

BUG=564965
==========

to

==========
The underlying WebRTC objects maintain all the needed references.
No references are actually needed in the blink layer.

BUG=564965
==========

[commit-bot: I haz the power, 2016-01-27 01:08:30]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-01-27 01:09:31]

Description was changed from

==========
The underlying WebRTC objects maintain all the needed references.
No references are actually needed in the blink layer.

BUG=564965
==========

to

==========
The underlying WebRTC objects maintain all the needed references.
No references are actually needed in the blink layer.

BUG=564965

Committed: https://crrev.com/0004ce15cdf065966508c61a5265ae8662e363ed
Cr-Commit-Position: refs/heads/master@{#371667}
==========

[commit-bot: I haz the power, 2016-01-27 01:09:31]

Patchset 3 (id:??) landed as
https://crrev.com/0004ce15cdf065966508c61a5265ae8662e363ed
Cr-Commit-Position: refs/heads/master@{#371667}

[Guido Urdaneta, 2016-01-28 10:19:45]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/1641113002/ by guidou@chromium.org.

The reason for reverting is: It turns out that the underlying WebRTC DataChannel
 objects does not maintain a reference to the WebRTC PeerConnection, so we do
need to keep the reference in the blink layer.

PS2 was the correct patch..

[Taylor Brandstetter, 2016-01-28 18:46:03]

On 2016/01/28 10:19:45, Guido Urdaneta wrote:
> A revert of this CL (patchset #3 id:40001) has been created in
> https://codereview.chromium.org/1641113002/ by mailto:guidou@chromium.org.
> 
> The reason for reverting is: It turns out that the underlying WebRTC
DataChannel
>  objects does not maintain a reference to the WebRTC PeerConnection, so we do
> need to keep the reference in the blink layer.
> 
> PS2 was the correct patch..

Are you reverting this because it broke anything? The webrtc::DataChannel
doesn't directly have a reference to a PeerConnection, for design reasons; it
has a DataProviderInterface. And the creator of the DataChannel (PeerConnection)
calls OnTransportChannelDestroyed when the DataProviderInterface is no longer
safe to use. If this mechanism isn't working, I'd consider it a bug at the C++
level.

[Guido Urdaneta, 2016-01-29 15:56:59]

On 2016/01/28 18:46:03, Taylor Brandstetter wrote:
> On 2016/01/28 10:19:45, Guido Urdaneta wrote:
> > A revert of this CL (patchset #3 id:40001) has been created in
> > https://codereview.chromium.org/1641113002/ by mailto:guidou@chromium.org.
> > 
> > The reason for reverting is: It turns out that the underlying WebRTC
> DataChannel
> >  objects does not maintain a reference to the WebRTC PeerConnection, so we
do
> > need to keep the reference in the blink layer.
> > 
> > PS2 was the correct patch..
> 
> Are you reverting this because it broke anything? The webrtc::DataChannel
> doesn't directly have a reference to a PeerConnection, for design reasons; it
> has a DataProviderInterface. And the creator of the DataChannel
(PeerConnection)
> calls OnTransportChannelDestroyed when the DataProviderInterface is no longer
> safe to use. If this mechanism isn't working, I'd consider it a bug at the C++
> level.

There were concerns that we should have had the strong reference to
RTCPeerConnection in RTCDataChannel.
Nevertheless, we discussed this again and decided that we should reland this and
implement the strong reference in the libjingle layer.