Reland of Make rendering of MediaStreams reflect changes to its set of tracks.

Reland of Make rendering of MediaStreams reflect changes to its set of tracks. (patchset #1 id:1 of https://codereview.chromium.org/2985393002/ )

Reason for revert:
BUILD files have been fixed in a separate CL, so this is safe to reland.

Original issue's description:
> Revert of Make rendering of MediaStreams reflect changes to its set of tracks. (patchset #6 id:120001 of https://codereview.chromium.org/2969093002/ )
> 
> Reason for revert:
> Breaking build https://uberchromegw.corp.google.com/i/chromium.linux/builders/Cast%20Audio%20Linux/builds/3356
> 
> Original issue's description:
> > Make rendering of MediaStreams reflect changes to its set of tracks.
> > 
> > Before this CL, MediaStreams assigned to a media element required
> > reassignment of the stream to the element in order to make changes
> > to the set of tracks visible.
> > 
> > This CL fixes this problem by making WebMediaPlayerMS subscribe to
> > changes in the set of tracks of a MediaStream, and correspondingly
> > update audio and video renderers.
> > 
> > BUG=720258
> > 
> > Review-Url: https://codereview.chromium.org/2969093002
> > Cr-Commit-Position: refs/heads/master@{#490906}
> > Committed: https://chromium.googlesource.com/chromium/src/+/c9612ba8bf66e48a32301e35425dd3384f48a3d8
> 
> TBR=dalecurtis@chromium.org,emircan@chromium.org,foolip@chromium.org,mkwst@chromium.org,guidou@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=720258
> 
> Review-Url: https://codereview.chromium.org/2985393002
> Cr-Commit-Position: refs/heads/master@{#490920}
> Committed: https://chromium.googlesource.com/chromium/src/+/b35b4c271b7819e3661942ab2c72083673722910

TBR=dalecurtis@chromium.org,emircan@chromium.org,foolip@chromium.org,mkwst@chromium.org,jkrcal@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=720258
Review-Url: https://codereview.chromium.org/2994473002
Cr-Commit-Position: refs/heads/master@{#491341}
Committed: https://chromium.googlesource.com/chromium/src/+/92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0

[Guido Urdaneta, 2017-08-02 09:52:28]

Created Reland of Make rendering of MediaStreams reflect changes to its set of
tracks.

[Guido Urdaneta, 2017-08-02 09:52:37]

The CQ bit was checked by guidou@chromium.org

[Guido Urdaneta, 2017-08-02 09:52:38]

The CQ bit was unchecked by guidou@chromium.org

[Guido Urdaneta, 2017-08-02 09:52:53]

The CQ bit was checked by guidou@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-08-02 09:52:59]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[foolip, 2017-08-02 10:01:19]

lgtm

[jkrcal, 2017-08-02 10:48:22]

from previous sheriff's perspective: lgtm

[Guido Urdaneta, 2017-08-02 11:17:09]

The CQ bit was unchecked by guidou@chromium.org

[Guido Urdaneta, 2017-08-02 11:17:14]

The CQ bit was checked by guidou@chromium.org

[commit-bot: I haz the power, 2017-08-02 11:17:22]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-08-02 12:03:55]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1501672634813810, "parent_rev":
"87ff5bea8b03996847df29824e4b18368e6cc773", "commit_rev":
"92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0"}

[commit-bot: I haz the power, 2017-08-02 12:04:10]

Description was changed from

==========
Reland of Make rendering of MediaStreams reflect changes to its set of tracks.
(patchset #1 id:1 of https://codereview.chromium.org/2985393002/ )

Reason for revert:
BUILD files have been fixed in a separate CL, so this is safe to reland.

Original issue's description:
> Revert of Make rendering of MediaStreams reflect changes to its set of tracks.
(patchset #6 id:120001 of https://codereview.chromium.org/2969093002/ )
> 
> Reason for revert:
> Breaking build
https://uberchromegw.corp.google.com/i/chromium.linux/builders/Cast%20Audio%2...
> 
> Original issue's description:
> > Make rendering of MediaStreams reflect changes to its set of tracks.
> > 
> > Before this CL, MediaStreams assigned to a media element required
> > reassignment of the stream to the element in order to make changes
> > to the set of tracks visible.
> > 
> > This CL fixes this problem by making WebMediaPlayerMS subscribe to
> > changes in the set of tracks of a MediaStream, and correspondingly
> > update audio and video renderers.
> > 
> > BUG=720258
> > 
> > Review-Url: https://codereview.chromium.org/2969093002
> > Cr-Commit-Position: refs/heads/master@{#490906}
> > Committed:
https://chromium.googlesource.com/chromium/src/+/c9612ba8bf66e48a32301e35425d...
> 
>
TBR=dalecurtis@chromium.org,emircan@chromium.org,foolip@chromium.org,mkwst@ch...
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=720258
> 
> Review-Url: https://codereview.chromium.org/2985393002
> Cr-Commit-Position: refs/heads/master@{#490920}
> Committed:
https://chromium.googlesource.com/chromium/src/+/b35b4c271b7819e3661942ab2c72...

TBR=dalecurtis@chromium.org,emircan@chromium.org,foolip@chromium.org,mkwst@ch...
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=720258
==========

to

==========
Reland of Make rendering of MediaStreams reflect changes to its set of tracks.
(patchset #1 id:1 of https://codereview.chromium.org/2985393002/ )

Reason for revert:
BUILD files have been fixed in a separate CL, so this is safe to reland.

Original issue's description:
> Revert of Make rendering of MediaStreams reflect changes to its set of tracks.
(patchset #6 id:120001 of https://codereview.chromium.org/2969093002/ )
> 
> Reason for revert:
> Breaking build
https://uberchromegw.corp.google.com/i/chromium.linux/builders/Cast%20Audio%2...
> 
> Original issue's description:
> > Make rendering of MediaStreams reflect changes to its set of tracks.
> > 
> > Before this CL, MediaStreams assigned to a media element required
> > reassignment of the stream to the element in order to make changes
> > to the set of tracks visible.
> > 
> > This CL fixes this problem by making WebMediaPlayerMS subscribe to
> > changes in the set of tracks of a MediaStream, and correspondingly
> > update audio and video renderers.
> > 
> > BUG=720258
> > 
> > Review-Url: https://codereview.chromium.org/2969093002
> > Cr-Commit-Position: refs/heads/master@{#490906}
> > Committed:
https://chromium.googlesource.com/chromium/src/+/c9612ba8bf66e48a32301e35425d...
> 
>
TBR=dalecurtis@chromium.org,emircan@chromium.org,foolip@chromium.org,mkwst@ch...
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=720258
> 
> Review-Url: https://codereview.chromium.org/2985393002
> Cr-Commit-Position: refs/heads/master@{#490920}
> Committed:
https://chromium.googlesource.com/chromium/src/+/b35b4c271b7819e3661942ab2c72...

TBR=dalecurtis@chromium.org,emircan@chromium.org,foolip@chromium.org,mkwst@ch...
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=720258

Review-Url: https://codereview.chromium.org/2994473002
Cr-Commit-Position: refs/heads/master@{#491341}
Committed:
https://chromium.googlesource.com/chromium/src/+/92561aec1fac0748d4e0ac3618ed...
==========

[commit-bot: I haz the power, 2017-08-02 12:04:11]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/92561aec1fac0748d4e0ac3618ed...