--- a/dom/media/MediaStreamGraph.cpp
+++ b/dom/media/MediaStreamGraph.cpp
@@ -985,17 +985,17 @@ void MediaStreamGraphImpl::DeviceChanged
 
   if (!mInputDeviceID) {
     return;
   }
 
   nsTArray<RefPtr<AudioDataListener>>* listeners =
     mInputDeviceUsers.GetValue(mInputDeviceID);
   for (auto& listener : *listeners) {
-    listener->DeviceChanged();
+    listener->DeviceChanged(this);
   }
 }
 
 void MediaStreamGraphImpl::DeviceChanged()
 {
   // This is safe to be called from any thread: this message comes from an
   // underlying platform API, and we don't have much guarantees. If it is not
   // called from the main thread (and it probably will rarely be), it will post

--- a/dom/media/MediaStreamGraph.h
+++ b/dom/media/MediaStreamGraph.h
@@ -115,22 +115,22 @@ public:
    */
   virtual void NotifyInputData(MediaStreamGraph* aGraph,
                                const AudioDataValue* aBuffer, size_t aFrames,
                                TrackRate aRate, uint32_t aChannels) = 0;
 
   /**
    * Number of audio input channels.
    */
-  virtual uint32_t InputChannelCount() = 0;
+  virtual uint32_t InputChannelCount(MediaStreamGraph* aGraph) = 0;
 
   /**
    * Called when the underlying audio device has changed.
    */
-  virtual void DeviceChanged() = 0;
+  virtual void DeviceChanged(MediaStreamGraph* aGraph) = 0;
 };
 
 class AudioDataListener : public AudioDataListenerInterface {
 protected:
   // Protected destructor, to discourage deletion outside of Release():
   virtual ~AudioDataListener() {}
 
 public:

--- a/dom/media/MediaStreamGraphImpl.h
+++ b/dom/media/MediaStreamGraphImpl.h
@@ -475,17 +475,17 @@ public:
     uint32_t maxInputChannels = 0;
     // When/if we decide to support multiple input device per graph, this needs
     // loop over them.
     nsTArray<RefPtr<AudioDataListener>>* listeners =
       mInputDeviceUsers.GetValue(mInputDeviceID);
     MOZ_ASSERT(listeners);
     for (const auto& listener : *listeners) {
       maxInputChannels =
-        std::max(maxInputChannels, listener->InputChannelCount());
+        std::max(maxInputChannels, listener->InputChannelCount(this));
     }
     return maxInputChannels;
   }
 
   CubebUtils::AudioDeviceID InputDeviceID()
   {
     return mInputDeviceID;
   }

--- a/dom/media/webrtc/MediaEngineWebRTC.h
+++ b/dom/media/webrtc/MediaEngineWebRTC.h
@@ -180,19 +180,19 @@ public:
                         uint32_t aChannels) override;
 
   void NotifyInputData(MediaStreamGraph* aGraph,
                        const AudioDataValue* aBuffer,
                        size_t aFrames,
                        TrackRate aRate,
                        uint32_t aChannels) override;
 
-  uint32_t InputChannelCount() override;
+  uint32_t InputChannelCount(MediaStreamGraph* aGraph) override;
 
-  void DeviceChanged() override;
+  void DeviceChanged(MediaStreamGraph* aGraph) override;
 
   void Shutdown();
 
 private:
   Mutex mMutex;
   RefPtr<MediaEngineWebRTCMicrophoneSource> mAudioSource;
 };
 
@@ -249,19 +249,19 @@ public:
   // AudioDataListenerInterface methods
   void NotifyOutputData(MediaStreamGraph* aGraph,
                         AudioDataValue* aBuffer, size_t aFrames,
                         TrackRate aRate, uint32_t aChannels) override;
   void NotifyInputData(MediaStreamGraph* aGraph,
                        const AudioDataValue* aBuffer, size_t aFrames,
                        TrackRate aRate, uint32_t aChannels) override;
 
-  void DeviceChanged() override;
+  void DeviceChanged(MediaStreamGraph* aGraph) override;
 
-  uint32_t InputChannelCount() override
+  uint32_t InputChannelCount(MediaStreamGraph* aGraph) override
   {
     return GetRequestedInputChannelCount();
   }
 
   dom::MediaSourceEnum GetMediaSource() const override
   {
     return dom::MediaSourceEnum::Microphone;
   }

--- a/dom/media/webrtc/MediaEngineWebRTCAudio.cpp
+++ b/dom/media/webrtc/MediaEngineWebRTCAudio.cpp
@@ -73,28 +73,30 @@ WebRTCAudioDataListener::NotifyInputData
 {
   MOZ_ASSERT(static_cast<MediaStreamGraphImpl*>(aGraph)->CurrentDriver()->OnThread());
   if (mAudioSource) {
     mAudioSource->NotifyInputData(aGraph, aBuffer, aFrames, aRate, aChannels);
   }
 }
 
 void
-WebRTCAudioDataListener::DeviceChanged()
+WebRTCAudioDataListener::DeviceChanged(MediaStreamGraph* aGraph)
 {
+  MOZ_ASSERT(static_cast<MediaStreamGraphImpl*>(aGraph)->CurrentDriver()->OnThread());
   if (mAudioSource) {
-    mAudioSource->DeviceChanged();
+    mAudioSource->DeviceChanged(aGraph);
   }
 }
 
 uint32_t
-WebRTCAudioDataListener::InputChannelCount()
+WebRTCAudioDataListener::InputChannelCount(MediaStreamGraph* aGraph)
 {
+  MOZ_ASSERT(static_cast<MediaStreamGraphImpl*>(aGraph)->CurrentDriver()->OnThread());
   if (mAudioSource) {
-    return mAudioSource->InputChannelCount();
+    return mAudioSource->InputChannelCount(aGraph);
   }
   return 0;
 }
 
 void
 WebRTCAudioDataListener::Shutdown()
 {
   mAudioSource = nullptr;
@@ -1214,17 +1216,17 @@ do {                                    
       #_processing " on device change.");                           \
       return;                                                       \
     }                                                               \
                                                                     \
   }                                                                 \
 }  while(0)
 
 void
-MediaEngineWebRTCMicrophoneSource::DeviceChanged()
+MediaEngineWebRTCMicrophoneSource::DeviceChanged(MediaStreamGraph* aGraph)
 {
   MOZ_ASSERT(!mAllocations.IsEmpty() &&
              mAllocations[0].mStream &&
              mAllocations[0].mStream->GraphImpl()->CurrentDriver()->OnThread());
   // Reset some processing
   ResetProcessingIfNeeded(gain_control);
   ResetProcessingIfNeeded(echo_cancellation);
   ResetProcessingIfNeeded(noise_suppression);