Revert of MediaStream audio object graph untangling and clean-ups.

Revert of MediaStream audio object graph untangling and clean-ups. (patchset #10 id:200001 of https://codereview.chromium.org/1721273002/ )

Reason for revert:
Broke a number of mediastream/ tests, e.g., https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Trusty/builds/9786

Original issue's description:
> MediaStream audio object graph untangling and clean-ups.
>
> This change consists of a number of "clean-up" changes that are being
> done to make the soon-upcoming refactoring of these classes go much more
> smoothly.  These are:
>
> 1. Public content MediaStreamApi functions cleaned up.  Removed
> "duplicated" functions that don't really do the same thing.  Removed
> hard-coded audio parameters from AddAudioTrackToMediaStream().
>
> 2. Eliminated ref-counting of WebRtcAudioCapturer and
> WebAudioCaptureSource.  Removed unnecessary references to these from
> WebRtcLocalAudioTrack.  Not only did this improve encapsulation of some
> code, but it also allowed for the removal of several dozen lines of
> "dead weight" testing set-upcode throughout the directory.
>
> 3. Renamed MediaStreamAudioTrack::GetTrack() method to From(), to be
> consistent with how this pattern is used in other parts of libcontent,
> and added a MediaStreamAudioSource::From().
>
> 4. Moved audio level calculations out of WebRtcLocalAudioTrack and into
> WebRtcAudioCapturer.  This way, when multiple tracks are present, the
> calculation is only being done once on the same audio.
>
> 5. Eliminated call to WebRtcCapturer::Stop() from
> WebRtcAudioDeviceImpl::Terminate(), which are each supposed to run on
> different threads.  From testing, DCHECKs should have been firing, but
> weren't, so the Terminate() method seems to be dead code.
>
> 6. Miscellaneous other "compaction" and comment updates.
>
> BUG=577881, 577874
> TBR=peter@chromium.org
>
> Committed: https://crrev.com/26bfd80549511a7e05f23c9941c41ced104ddf28
> Cr-Commit-Position: refs/heads/master@{#380065}

TBR=jochen@chromium.org,finnur@chromium.org,mcasas@chromium.org,olka@chromium.org,peter@chromium.org,tommi@chromium.org,miu@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=577881, 577874
Committed: https://crrev.com/0a40d9db89298db3edb7cbb49488db1100e0cdbb
Cr-Commit-Position: refs/heads/master@{#380103}

[sof, 2016-03-09 08:49:17]

Created Revert of MediaStream audio object graph untangling and clean-ups.

[commit-bot: I haz the power, 2016-03-09 08:49:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1780653002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1780653002/1

[commit-bot: I haz the power, 2016-03-09 08:50:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-09 08:51:41]

Description was changed from

==========
Revert of MediaStream audio object graph untangling and clean-ups. (patchset #10
id:200001 of https://codereview.chromium.org/1721273002/ )

Reason for revert:
Broke a number of mediastream/ tests, e.g.,
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Trusty...

Original issue's description:
> MediaStream audio object graph untangling and clean-ups.
> 
> This change consists of a number of "clean-up" changes that are being
> done to make the soon-upcoming refactoring of these classes go much more
> smoothly.  These are:
> 
> 1. Public content MediaStreamApi functions cleaned up.  Removed
> "duplicated" functions that don't really do the same thing.  Removed
> hard-coded audio parameters from AddAudioTrackToMediaStream().
> 
> 2. Eliminated ref-counting of WebRtcAudioCapturer and
> WebAudioCaptureSource.  Removed unnecessary references to these from
> WebRtcLocalAudioTrack.  Not only did this improve encapsulation of some
> code, but it also allowed for the removal of several dozen lines of
> "dead weight" testing set-upcode throughout the directory.
> 
> 3. Renamed MediaStreamAudioTrack::GetTrack() method to From(), to be
> consistent with how this pattern is used in other parts of libcontent,
> and added a MediaStreamAudioSource::From().
> 
> 4. Moved audio level calculations out of WebRtcLocalAudioTrack and into
> WebRtcAudioCapturer.  This way, when multiple tracks are present, the
> calculation is only being done once on the same audio.
> 
> 5. Eliminated call to WebRtcCapturer::Stop() from
> WebRtcAudioDeviceImpl::Terminate(), which are each supposed to run on
> different threads.  From testing, DCHECKs should have been firing, but
> weren't, so the Terminate() method seems to be dead code.
> 
> 6. Miscellaneous other "compaction" and comment updates.
> 
> BUG=577881, 577874
> TBR=peter@chromium.org
> 
> Committed: https://crrev.com/26bfd80549511a7e05f23c9941c41ced104ddf28
> Cr-Commit-Position: refs/heads/master@{#380065}

TBR=jochen@chromium.org,finnur@chromium.org,mcasas@chromium.org,olka@chromium...
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=577881, 577874
==========

to

==========
Revert of MediaStream audio object graph untangling and clean-ups. (patchset #10
id:200001 of https://codereview.chromium.org/1721273002/ )

Reason for revert:
Broke a number of mediastream/ tests, e.g.,
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Trusty...

Original issue's description:
> MediaStream audio object graph untangling and clean-ups.
>
> This change consists of a number of "clean-up" changes that are being
> done to make the soon-upcoming refactoring of these classes go much more
> smoothly.  These are:
>
> 1. Public content MediaStreamApi functions cleaned up.  Removed
> "duplicated" functions that don't really do the same thing.  Removed
> hard-coded audio parameters from AddAudioTrackToMediaStream().
>
> 2. Eliminated ref-counting of WebRtcAudioCapturer and
> WebAudioCaptureSource.  Removed unnecessary references to these from
> WebRtcLocalAudioTrack.  Not only did this improve encapsulation of some
> code, but it also allowed for the removal of several dozen lines of
> "dead weight" testing set-upcode throughout the directory.
>
> 3. Renamed MediaStreamAudioTrack::GetTrack() method to From(), to be
> consistent with how this pattern is used in other parts of libcontent,
> and added a MediaStreamAudioSource::From().
>
> 4. Moved audio level calculations out of WebRtcLocalAudioTrack and into
> WebRtcAudioCapturer.  This way, when multiple tracks are present, the
> calculation is only being done once on the same audio.
>
> 5. Eliminated call to WebRtcCapturer::Stop() from
> WebRtcAudioDeviceImpl::Terminate(), which are each supposed to run on
> different threads.  From testing, DCHECKs should have been firing, but
> weren't, so the Terminate() method seems to be dead code.
>
> 6. Miscellaneous other "compaction" and comment updates.
>
> BUG=577881, 577874
> TBR=peter@chromium.org
>
> Committed: https://crrev.com/26bfd80549511a7e05f23c9941c41ced104ddf28
> Cr-Commit-Position: refs/heads/master@{#380065}

TBR=jochen@chromium.org,finnur@chromium.org,mcasas@chromium.org,olka@chromium...
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=577881, 577874

Committed: https://crrev.com/0a40d9db89298db3edb7cbb49488db1100e0cdbb
Cr-Commit-Position: refs/heads/master@{#380103}
==========

[commit-bot: I haz the power, 2016-03-09 08:51:43]

Patchset 1 (id:??) landed as
https://crrev.com/0a40d9db89298db3edb7cbb49488db1100e0cdbb
Cr-Commit-Position: refs/heads/master@{#380103}