meh. Can someone change the title to "getUserMedia: adding a video track to a stream with an audio-only srcObject does not show video" please?

https://jsfiddle.net/f4uqtgn7/2/ is putting this into the wpt harness (thanks foolip!)
Had to add a workaround for  issue 601470  :-/

I can reproduce.

i've made a PR with a sample: https://github.com/webrtc/samples/pull/906
Including workarounds because the Edge behaviour for remote streams is odd too :-)

ping -- I am considering adding a really ugly workaround in adapter since that is less evil than spreading a document.querySelectorAll('video') srcObject re-setter everywhere.

philipp.hancke@: see https://codereview.chromium.org/2969093002/

woho, thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c9612ba8bf66e48a32301e35425dd3384f48a3d8

commit c9612ba8bf66e48a32301e35425dd3384f48a3d8
Author: guidou <guidou@chromium.org>
Date: Tue Aug 01 07:42:47 2017

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}

[modify] https://crrev.com/c9612ba8bf66e48a32301e35425dd3384f48a3d8/content/browser/webrtc/webrtc_getusermedia_browsertest.cc
[modify] https://crrev.com/c9612ba8bf66e48a32301e35425dd3384f48a3d8/content/renderer/media/webmediaplayer_ms.cc
[modify] https://crrev.com/c9612ba8bf66e48a32301e35425dd3384f48a3d8/content/renderer/media/webmediaplayer_ms.h
[modify] https://crrev.com/c9612ba8bf66e48a32301e35425dd3384f48a3d8/content/shell/test_runner/mock_web_user_media_client.cc
[modify] https://crrev.com/c9612ba8bf66e48a32301e35425dd3384f48a3d8/content/test/data/media/getusermedia.html

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b35b4c271b7819e3661942ab2c72083673722910

commit b35b4c271b7819e3661942ab2c72083673722910
Author: jkrcal <jkrcal@chromium.org>
Date: Tue Aug 01 08:55:08 2017

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}

[modify] https://crrev.com/b35b4c271b7819e3661942ab2c72083673722910/content/browser/webrtc/webrtc_getusermedia_browsertest.cc
[modify] https://crrev.com/b35b4c271b7819e3661942ab2c72083673722910/content/renderer/media/webmediaplayer_ms.cc
[modify] https://crrev.com/b35b4c271b7819e3661942ab2c72083673722910/content/renderer/media/webmediaplayer_ms.h
[modify] https://crrev.com/b35b4c271b7819e3661942ab2c72083673722910/content/shell/test_runner/mock_web_user_media_client.cc
[modify] https://crrev.com/b35b4c271b7819e3661942ab2c72083673722910/content/test/data/media/getusermedia.html

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0

commit 92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0
Author: guidou <guidou@chromium.org>
Date: Wed Aug 02 12:03:53 2017

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}

[modify] https://crrev.com/92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0/content/browser/webrtc/webrtc_getusermedia_browsertest.cc
[modify] https://crrev.com/92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0/content/renderer/media/webmediaplayer_ms.cc
[modify] https://crrev.com/92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0/content/renderer/media/webmediaplayer_ms.h
[modify] https://crrev.com/92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0/content/shell/test_runner/mock_web_user_media_client.cc
[modify] https://crrev.com/92561aec1fac0748d4e0ac3618ed7d2eb6ea9cb0/content/test/data/media/getusermedia.html