Detect AudioInputStream muting and propagate to MediaStreamAudioSource.

third_party/WebKit/Source/modules/mediastream/MediaStreamTrack.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Ericsson AB. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 54 matching lines @@
                                    MediaStreamComponent* component)
     : ContextLifecycleObserver(context),
       ready_state_(MediaStreamSource::kReadyStateLive),
       is_iterating_registered_media_streams_(false),
       stopped_(false),
       component_(component),
       // The source's constraints aren't yet initialized at creation time.
       constraints_() {
   component_->Source()->AddObserver(this);
 
+  // If the source is already non-live at this point, the observer won't have
+  // been called. Check the state manually.
+  if (ready_state_ != component_->Source()->GetReadyState())
+    SourceChangedState();

[Max Morin, 2017/06/02 09:56:05]

You seem to be calling a virtual method from the constructor which is usually
scary. Maybe you can make it final?

[ossu-chromium, 2017/06/02 10:48:00]

You're right. I actually only need to add a check for Muted and then call
component_->SetMuted(). The rest SourceChangedState will just never happen
(since the default ready_state_ is Live).

+
   if (component_->Source() &&
       component_->Source()->GetType() == MediaStreamSource::kTypeVideo) {
     // ImageCapture::create() only throws if |this| track is not of video type.
     NonThrowableExceptionState exception_state;
     image_capture_ = ImageCapture::Create(context, this, exception_state);
   }
 }
 
 MediaStreamTrack::~MediaStreamTrack() {}
 
@@ skipping 324 matching lines @@
 
 DEFINE_TRACE(MediaStreamTrack) {
   visitor->Trace(registered_media_streams_);
   visitor->Trace(component_);
   visitor->Trace(image_capture_);
   EventTargetWithInlineData::Trace(visitor);
   ContextLifecycleObserver::Trace(visitor);
 }
 
 }  // namespace blink