Reland of Adding the ability to create an RtpSender without a track.

Reland of Adding the ability to create an RtpSender without a track.
(patchset #8 id:140001 of https://codereview.webrtc.org/1413713003/ )

Relanding after fixing CallAndModifyStream to account for new
procedures for adding/removing a track from a stream.

Original issue's description:
> Adding the ability to create an RtpSender without a track.
>
> This CL also changes AddStream to immediately create a sender, rather
> than waiting until the track is seen in SDP. And the PeerConnection now
> builds the list of "send streams" from the list of senders, rather than
> the collection of local media streams.
>
> Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> Cr-Commit-Position: refs/heads/master@{#10414}

Committed: https://crrev.com/fac0655fd7fe0b40ef50dc5b7f11ea44d72cec6c
Cr-Commit-Position: refs/heads/master@{#10790}

[Taylor Brandstetter, 2015-11-23 17:53:31]

Created Reland of Adding the ability to create an RtpSender without a track.

[Taylor Brandstetter, 2015-11-23 17:57:25]

Description was changed from

==========
Reland of Adding the ability to create an RtpSender without a track. (patchset
#1 id:1 of https://codereview.webrtc.org/1460323002/ )

Reason for revert:
Relanding again, after fixing CallAndModifyStream again.

Original issue's description:
> Revert of Adding the ability to create an RtpSender without a track. (patchset
#3 id:300001 of https://codereview.webrtc.org/1413983004/ )
> 
> Reason for revert:
> Still breaking CallAndModifyStream. Chromium CL intended to fix it
(https://codereview.chromium.org/1435713002/) wasn't sufficient, because I
forgot to call addStream/removeStream on the second connection.
> 
> Original issue's description:
> > Reland of Adding the ability to create an RtpSender without a track.
(patchset #1 id:1 of https://codereview.webrtc.org/1426443007/ )
> >
> > Reason for revert:
> > Relanding, after changing the expectations of
WebRtcBrowserTest.CallAndModifyStream.
> >
> > Original issue's description:
> > > Revert of Adding the ability to create an RtpSender without a track.
(patchset #8 id:140001 of https://codereview.webrtc.org/1413713003/ )
> > >
> > > Reason for revert:
> > > Causing a compiler warning, and causing
WebRtcBrowserTest.CallAndModifyStream to fail.
> > >
> > > Original issue's description:
> > > > Adding the ability to create an RtpSender without a track.
> > > >
> > > > This CL also changes AddStream to immediately create a sender, rather
> > > > than waiting until the track is seen in SDP. And the PeerConnection now
> > > > builds the list of "send streams" from the list of senders, rather than
> > > > the collection of local media streams.
> > > >
> > > > Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> > > > Cr-Commit-Position: refs/heads/master@{#10414}
> > >
> > > TBR=pthatcher@webrtc.org,pthatcher@chromium.org
> > > NOPRESUBMIT=true
> > > NOTREECHECKS=true
> > > NOTRY=true
> > >
> > > Committed: https://crrev.com/8f46c63f6f764254892f4111b54aa1cc8f32eeeb
> > > Cr-Commit-Position: refs/heads/master@{#10417}
> >
> > TBR=pthatcher@webrtc.org,pthatcher@chromium.org
> > NOPRESUBMIT=true
> > NOTREECHECKS=true
> > NOTRY=true
> >
> > Committed: https://crrev.com/6834fa10f142bf5e2275142acb834898911d09ae
> > Cr-Commit-Position: refs/heads/master@{#10730}
> 
> TBR=pthatcher@webrtc.org,pthatcher@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> 
> Committed: https://crrev.com/5def7b9fdea0d027bca3df734d86fb877a83bdbf
> Cr-Commit-Position: refs/heads/master@{#10732}

TBR=pthatcher@webrtc.org,pthatcher@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
==========

to

==========
Reland of Adding the ability to create an RtpSender without a track. (patchset
#8 id:140001 of https://codereview.webrtc.org/1413713003/ )

Original issue's description:
> Adding the ability to create an RtpSender without a track.
>
> This CL also changes AddStream to immediately create a sender, rather
> than waiting until the track is seen in SDP. And the PeerConnection now
> builds the list of "send streams" from the list of senders, rather than
> the collection of local media streams.
>
> Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> Cr-Commit-Position: refs/heads/master@{#10414}
==========

[Taylor Brandstetter, 2015-11-23 18:15:32]

Description was changed from

==========
Reland of Adding the ability to create an RtpSender without a track. (patchset
#8 id:140001 of https://codereview.webrtc.org/1413713003/ )

Original issue's description:
> Adding the ability to create an RtpSender without a track.
>
> This CL also changes AddStream to immediately create a sender, rather
> than waiting until the track is seen in SDP. And the PeerConnection now
> builds the list of "send streams" from the list of senders, rather than
> the collection of local media streams.
>
> Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> Cr-Commit-Position: refs/heads/master@{#10414}
==========

to

==========
Reland of Adding the ability to create an RtpSender without a track.
(patchset #8 id:140001 of https://codereview.webrtc.org/1413713003/ )

Relanding after fixing CallAndModifyStream to account for new
procedures for adding/removing a track from a stream.

Original issue's description:
> Adding the ability to create an RtpSender without a track.
>
> This CL also changes AddStream to immediately create a sender, rather
> than waiting until the track is seen in SDP. And the PeerConnection now
> builds the list of "send streams" from the list of senders, rather than
> the collection of local media streams.
>
> Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> Cr-Commit-Position: refs/heads/master@{#10414}
==========

[pthatcher1, 2015-11-23 20:39:28]

lgtm

[Taylor Brandstetter, 2015-11-25 17:36:13]

The CQ bit was checked by deadbeef@webrtc.org

[commit-bot: I haz the power, 2015-11-25 17:36:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1468113002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1468113002/1

[commit-bot: I haz the power, 2015-11-25 19:26:04]

Description was changed from

==========
Reland of Adding the ability to create an RtpSender without a track.
(patchset #8 id:140001 of https://codereview.webrtc.org/1413713003/ )

Relanding after fixing CallAndModifyStream to account for new
procedures for adding/removing a track from a stream.

Original issue's description:
> Adding the ability to create an RtpSender without a track.
>
> This CL also changes AddStream to immediately create a sender, rather
> than waiting until the track is seen in SDP. And the PeerConnection now
> builds the list of "send streams" from the list of senders, rather than
> the collection of local media streams.
>
> Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> Cr-Commit-Position: refs/heads/master@{#10414}
==========

to

==========
Reland of Adding the ability to create an RtpSender without a track.
(patchset #8 id:140001 of https://codereview.webrtc.org/1413713003/ )

Relanding after fixing CallAndModifyStream to account for new
procedures for adding/removing a track from a stream.

Original issue's description:
> Adding the ability to create an RtpSender without a track.
>
> This CL also changes AddStream to immediately create a sender, rather
> than waiting until the track is seen in SDP. And the PeerConnection now
> builds the list of "send streams" from the list of senders, rather than
> the collection of local media streams.
>
> Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> Cr-Commit-Position: refs/heads/master@{#10414}
==========

[commit-bot: I haz the power, 2015-11-25 19:26:05]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-25 19:26:11]

Description was changed from

==========
Reland of Adding the ability to create an RtpSender without a track.
(patchset #8 id:140001 of https://codereview.webrtc.org/1413713003/ )

Relanding after fixing CallAndModifyStream to account for new
procedures for adding/removing a track from a stream.

Original issue's description:
> Adding the ability to create an RtpSender without a track.
>
> This CL also changes AddStream to immediately create a sender, rather
> than waiting until the track is seen in SDP. And the PeerConnection now
> builds the list of "send streams" from the list of senders, rather than
> the collection of local media streams.
>
> Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> Cr-Commit-Position: refs/heads/master@{#10414}
==========

to

==========
Reland of Adding the ability to create an RtpSender without a track.
(patchset #8 id:140001 of https://codereview.webrtc.org/1413713003/ )

Relanding after fixing CallAndModifyStream to account for new
procedures for adding/removing a track from a stream.

Original issue's description:
> Adding the ability to create an RtpSender without a track.
>
> This CL also changes AddStream to immediately create a sender, rather
> than waiting until the track is seen in SDP. And the PeerConnection now
> builds the list of "send streams" from the list of senders, rather than
> the collection of local media streams.
>
> Committed: https://crrev.com/ac9d92ccbe2b29590c53f702e11dc625820480d5
> Cr-Commit-Position: refs/heads/master@{#10414}

Committed: https://crrev.com/fac0655fd7fe0b40ef50dc5b7f11ea44d72cec6c
Cr-Commit-Position: refs/heads/master@{#10790}
==========

[commit-bot: I haz the power, 2015-11-25 19:26:12]

Patchset 1 (id:??) landed as
https://crrev.com/fac0655fd7fe0b40ef50dc5b7f11ea44d72cec6c
Cr-Commit-Position: refs/heads/master@{#10790}