diff --git a/dom/media/webrtc/MediaEngineWebRTC.cpp b/dom/media/webrtc/MediaEngineWebRTC.cpp
index ca4f840bca94..db1dbcbf7cf6 100644
--- a/dom/media/webrtc/MediaEngineWebRTC.cpp
+++ b/dom/media/webrtc/MediaEngineWebRTC.cpp
@@ -45,7 +45,6 @@ GetUserMediaLog()
 namespace mozilla {
 
 cubeb_device_collection* AudioInputCubeb::mDevices = nullptr;
-bool AudioInputCubeb::mAnyInUse = false;
 
 MediaEngineWebRTC::MediaEngineWebRTC(MediaEnginePrefs &aPrefs)
   : mMutex("mozilla::MediaEngineWebRTC"),
diff --git a/dom/media/webrtc/MediaEngineWebRTC.h b/dom/media/webrtc/MediaEngineWebRTC.h
index 0a9557621d65..2a982c363149 100644
--- a/dom/media/webrtc/MediaEngineWebRTC.h
+++ b/dom/media/webrtc/MediaEngineWebRTC.h
@@ -159,7 +159,7 @@ class AudioInputCubeb final : public AudioInput
 {
 public:
   explicit AudioInputCubeb(webrtc::VoiceEngine* aVoiceEngine) :
-    AudioInput(aVoiceEngine), mSelectedDevice(0), mInUse(false)
+    AudioInput(aVoiceEngine), mSelectedDevice(0)
   {
     // Force calculation of the indexes.  We could keep them global
     // too... cleanup would be annoying
@@ -242,15 +242,11 @@ public:
       ptrVoERender->SetExternalRecordingStatus(true);
     }
     aGraph->OpenAudioInput(mDevices->device[mSelectedDevice]->devid, aListener);
-    mInUse = true;
-    mAnyInUse = true;
   }
 
   void StopRecording(MediaStreamGraph *aGraph, AudioDataListener *aListener)
   {
     aGraph->CloseAudioInput(aListener);
-    mInUse = false;
-    mAnyInUse = false;
   }
 
   int SetRecordingDevice(int aIndex)
@@ -264,16 +260,12 @@ public:
   }
 
 protected:
-  ~AudioInputCubeb() {
-    MOZ_RELEASE_ASSERT(!mInUse);
-  }
+  ~AudioInputCubeb() {}
 
 private:
   nsTArray<int> mDeviceIndexes;
   int mSelectedDevice;
   static cubeb_device_collection *mDevices;
-  bool mInUse; // for assertions about listener lifetime
-  static bool mAnyInUse;
 };
 
 class AudioInputWebRTC final : public AudioInput