diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index b9b53956f7c6..af4ebc505703 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -2519,10 +2519,6 @@ HTMLMediaElement::Seek(double aTime,
   //       MediaDecoderReaders.
 
   mPlayingBeforeSeek = IsPotentiallyPlaying();
-  // Set the Variable if the Seekstarted while active playing
-  if (mPlayingThroughTheAudioChannel) {
-    mPlayingThroughTheAudioChannelBeforeSeek = true;
-  }
 
   // The media backend is responsible for dispatching the timeupdate
   // event if it changes the playback position as a result of the seek.
@@ -3458,14 +3454,11 @@ HTMLMediaElement::HTMLMediaElement(already_AddRefed<mozilla::dom::NodeInfo>& aNo
     mAutoplayEnabled(true),
     mPaused(true),
     mMuted(0),
-    mAudioChannelSuspended(nsISuspendedTypes::NONE_SUSPENDED),
     mStatsShowing(false),
     mAllowCasting(false),
     mIsCasting(false),
     mAudioCaptured(false),
-    mAudioCapturedByWindow(false),
     mPlayingBeforeSeek(false),
-    mPlayingThroughTheAudioChannelBeforeSeek(false),
     mPausedForInactiveDocumentOrChannel(false),
     mEventDeliveryPaused(false),
     mIsRunningLoadMethod(false),
@@ -3487,14 +3480,11 @@ HTMLMediaElement::HTMLMediaElement(already_AddRefed<mozilla::dom::NodeInfo>& aNo
     mWaitingForKey(NOT_WAITING_FOR_KEY),
     mDownloadSuspendedByCache(false, "HTMLMediaElement::mDownloadSuspendedByCache"),
     mAudioChannel(AudioChannelService::GetDefaultAudioChannel()),
-    mAudioChannelVolume(1.0),
-    mPlayingThroughTheAudioChannel(false),
     mDisableVideo(false),
     mHasUserInteraction(false),
     mFirstFrameLoaded(false),
     mDefaultPlaybackStartPosition(0.0),
     mIsAudioTrackAudible(false),
-    mAudible(IsAudible()),
     mVisibilityState(Visibility::APPROXIMATELY_NONVISIBLE),
     mErrorSink(new ErrorSink(this)),
     mAudioChannelWrapper(new AudioChannelAgentCallback(this, mAudioChannel))
@@ -3516,7 +3506,6 @@ HTMLMediaElement::HTMLMediaElement(already_AddRefed<mozilla::dom::NodeInfo>& aNo
   mWatchManager.Watch(mReadyState, &HTMLMediaElement::UpdateReadyStateInternal);
 
   mShutdownObserver->Subscribe(this);
-  MaybeCreateAudioChannelAgent();
 }
 
 HTMLMediaElement::~HTMLMediaElement()
@@ -3557,7 +3546,6 @@ HTMLMediaElement::~HTMLMediaElement()
   }
 
   WakeLockRelease();
-  mAudioChannelAgent = nullptr;
 }
 
 void HTMLMediaElement::StopSuspendingAfterFirstFrame()
@@ -5093,8 +5081,6 @@ void HTMLMediaElement::SeekCompleted()
   if (mCurrentPlayRangeStart == -1.0) {
     mCurrentPlayRangeStart = CurrentTime();
   }
-  // Unset the variable on seekend
-  mPlayingThroughTheAudioChannelBeforeSeek = false;
 }
 
 void HTMLMediaElement::NotifySuspendedByCache(bool aIsSuspended)
@@ -6337,74 +6323,6 @@ ImageContainer* HTMLMediaElement::GetImageContainer()
   return container ? container->GetImageContainer() : nullptr;
 }
 
-bool
-HTMLMediaElement::MaybeCreateAudioChannelAgent()
-{
-  if (mAudioChannelAgent) {
-    return true;
-  }
-
-  mAudioChannelAgent = new AudioChannelAgent();
-  nsresult rv = mAudioChannelAgent->InitWithWeakCallback(OwnerDoc()->GetInnerWindow(),
-                                           static_cast<int32_t>(mAudioChannel),
-                                           this);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    mAudioChannelAgent = nullptr;
-    MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
-           ("HTMLMediaElement, Fail to initialize the audio channel agent,"
-            " this = %p\n", this));
-    return false;
-  }
-
-  return true;
-}
-
-bool
-HTMLMediaElement::IsPlayingThroughTheAudioChannel() const
-{
-  // If we have an error, we are not playing.
-  if (mErrorSink->mError) {
-    return false;
-  }
-
-  // It might be resumed from remote, we should keep the audio channel agent.
-  if (IsSuspendedByAudioChannel()) {
-    return true;
-  }
-
-  // Are we paused
-  if (mPaused) {
-    return false;
-  }
-
-  // We should consider any bfcached page or inactive document as non-playing.
-  if (!IsActive()) {
-    return false;
-  }
-
-  // A loop always is playing
-  if (HasAttr(kNameSpaceID_None, nsGkAtoms::loop)) {
-    return true;
-  }
-
-  // If we are actually playing...
-  if (IsCurrentlyPlaying()) {
-    return true;
-  }
-
-  // If we are seeking, we consider it as playing
-  if (mPlayingThroughTheAudioChannelBeforeSeek) {
-    return true;
-  }
-
-  // If we are playing an external stream.
-  if (mSrcAttrStream) {
-    return true;
-  }
-
-  return false;
-}
-
 void
 HTMLMediaElement::UpdateAudioChannelPlayingState(bool aForcePlaying)
 {
@@ -6413,177 +6331,6 @@ HTMLMediaElement::UpdateAudioChannelPlayingState(bool aForcePlaying)
   }
 }
 
-void
-HTMLMediaElement::NotifyAudioChannelAgent(bool aPlaying)
-{
-  if (aPlaying) {
-    // The reason we don't call NotifyStartedPlaying after the media element
-    // really becomes audible is because there is another case needs to block
-    // element as early as we can, we would hear sound leaking if we block it
-    // too late. In that case (block autoplay in non-visited-tab), we need to
-    // create a connection before decoding, because we don't want user hearing
-    // any sound.
-    AudioPlaybackConfig config;
-    nsresult rv = mAudioChannelAgent->NotifyStartedPlaying(&config,
-                                                           IsAudible());
-    if (NS_WARN_IF(NS_FAILED(rv))) {
-      return;
-    }
-
-    WindowVolumeChanged(config.mVolume, config.mMuted);
-    WindowSuspendChanged(config.mSuspend);
-  } else {
-    mAudioChannelAgent->NotifyStoppedPlaying();
-  }
-}
-
-NS_IMETHODIMP
-HTMLMediaElement::WindowVolumeChanged(float aVolume, bool aMuted)
-{
-  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
-         ("HTMLMediaElement, WindowVolumeChanged, this = %p, "
-          "aVolume = %f, aMuted = %d\n", this, aVolume, aMuted));
-
-  if (mAudioChannelVolume != aVolume) {
-    mAudioChannelVolume = aVolume;
-    SetVolumeInternal();
-  }
-
-  if (aMuted && !ComputedMuted()) {
-    SetMutedInternal(mMuted | MUTED_BY_AUDIO_CHANNEL);
-  } else if (!aMuted && ComputedMuted()) {
-    SetMutedInternal(mMuted & ~MUTED_BY_AUDIO_CHANNEL);
-  }
-
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-HTMLMediaElement::WindowSuspendChanged(SuspendTypes aSuspend)
-{
-  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
-         ("HTMLMediaElement, WindowSuspendChanged, this = %p, "
-          "aSuspend = %d\n", this, aSuspend));
-
-  switch (aSuspend) {
-    case nsISuspendedTypes::NONE_SUSPENDED:
-      ResumeFromAudioChannel();
-      break;
-    case nsISuspendedTypes::SUSPENDED_PAUSE:
-    case nsISuspendedTypes::SUSPENDED_PAUSE_DISPOSABLE:
-      PauseByAudioChannel(aSuspend);
-      break;
-    case nsISuspendedTypes::SUSPENDED_BLOCK:
-      BlockByAudioChannel();
-      break;
-    case nsISuspendedTypes::SUSPENDED_STOP_DISPOSABLE:
-      SetAudioChannelSuspended(nsISuspendedTypes::NONE_SUSPENDED);
-      Pause();
-      break;
-    default:
-      MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
-             ("HTMLMediaElement, WindowSuspendChanged, this = %p, "
-              "Error : unknown suspended type!\n", this));
-  }
-
-  return NS_OK;
-}
-
-void
-HTMLMediaElement::ResumeFromAudioChannel()
-{
-  if (!IsSuspendedByAudioChannel()) {
-    return;
-  }
-
-  switch (mAudioChannelSuspended) {
-    case nsISuspendedTypes::SUSPENDED_PAUSE:
-    case nsISuspendedTypes::SUSPENDED_PAUSE_DISPOSABLE:
-      ResumeFromAudioChannelPaused(mAudioChannelSuspended);
-      break;
-    case nsISuspendedTypes::SUSPENDED_BLOCK:
-      ResumeFromAudioChannelBlocked();
-      break;
-    default:
-      MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
-             ("HTMLMediaElement, ResumeFromAudioChannel, this = %p, "
-              "Error : resume without suspended!\n", this));
-  }
-}
-
-void
-HTMLMediaElement::ResumeFromAudioChannelPaused(SuspendTypes aSuspend)
-{
-  MOZ_ASSERT(mAudioChannelSuspended == nsISuspendedTypes::SUSPENDED_PAUSE ||
-             mAudioChannelSuspended == nsISuspendedTypes::SUSPENDED_PAUSE_DISPOSABLE);
-
-  SetAudioChannelSuspended(nsISuspendedTypes::NONE_SUSPENDED);
-  nsresult rv = Play();
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return;
-  }
-  DispatchAsyncEvent(NS_LITERAL_STRING("mozinterruptend"));
-}
-
-void
-HTMLMediaElement::ResumeFromAudioChannelBlocked()
-{
-  MOZ_ASSERT(mAudioChannelSuspended == nsISuspendedTypes::SUSPENDED_BLOCK);
-
-  SetAudioChannelSuspended(nsISuspendedTypes::NONE_SUSPENDED);
-  nsresult rv = Play();
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return;
-  }
-}
-
-void
-HTMLMediaElement::PauseByAudioChannel(SuspendTypes aSuspend)
-{
-  if (IsSuspendedByAudioChannel()) {
-    return;
-  }
-
-  SetAudioChannelSuspended(aSuspend);
-  Pause();
-  DispatchAsyncEvent(NS_LITERAL_STRING("mozinterruptbegin"));
-}
-
-void
-HTMLMediaElement::BlockByAudioChannel()
-{
-  if (IsSuspendedByAudioChannel()) {
-    return;
-  }
-
-  SetAudioChannelSuspended(nsISuspendedTypes::SUSPENDED_BLOCK);
-}
-
-void
-HTMLMediaElement::SetAudioChannelSuspended(SuspendTypes aSuspend)
-{
-  if (mAudioChannelSuspended == aSuspend) {
-    return;
-  }
-
-  MaybeNotifyMediaResumed(aSuspend);
-  mAudioChannelSuspended = aSuspend;
-  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
-         ("HTMLMediaElement, SetAudioChannelSuspended, this = %p, "
-          "aSuspend = %d\n", this, aSuspend));
-
-  NotifyAudioPlaybackChanged(
-    AudioChannelService::AudibleChangedReasons::ePauseStateChanged);
-}
-
-bool
-HTMLMediaElement::IsSuspendedByAudioChannel() const
-{
-  return (mAudioChannelSuspended == nsISuspendedTypes::SUSPENDED_PAUSE ||
-          mAudioChannelSuspended == nsISuspendedTypes::SUSPENDED_PAUSE_DISPOSABLE ||
-          mAudioChannelSuspended == nsISuspendedTypes::SUSPENDED_BLOCK);
-}
-
 bool
 HTMLMediaElement::IsAllowedToPlay()
 {
@@ -6611,36 +6358,6 @@ HTMLMediaElement::IsAllowedToPlay()
   return false;
 }
 
-bool
-HTMLMediaElement::IsAllowedToPlayByAudioChannel()
-{
-  // The media element has already been paused or blocked, so it can't start
-  // playback again by script or user's intend until resuming by audio channel.
-  if (mAudioChannelSuspended == nsISuspendedTypes::SUSPENDED_PAUSE ||
-      mAudioChannelSuspended == nsISuspendedTypes::SUSPENDED_BLOCK) {
-    return false;
-  }
-
-  // If the tab hasn't been activated yet, the media element in that tab can't
-  // be playback now until the tab goes to foreground first time or user clicks
-  // the unblocking tab icon.
-  if (MaybeCreateAudioChannelAgent() && !IsTabActivated()) {
-    // Even we haven't start playing yet, we still need to notify the audio
-    // channe system because we need to receive the resume notification later.
-    UpdateAudioChannelPlayingState(true /* force to start */);
-    return false;
-  }
-
-  return true;
-}
-
-bool
-HTMLMediaElement::IsTabActivated() const
-{
-  MOZ_ASSERT(mAudioChannelAgent);
-  return !mAudioChannelAgent->ShouldBlockMedia();
-}
-
 static const char* VisibilityString(Visibility aVisibility) {
   switch(aVisibility) {
     case Visibility::UNTRACKED: {
@@ -6922,17 +6639,6 @@ HTMLMediaElement::CannotDecryptWaitingForKey()
   }
 }
 
-NS_IMETHODIMP HTMLMediaElement::WindowAudioCaptureChanged(bool aCapture)
-{
-  MOZ_ASSERT(mAudioChannelAgent);
-
-  if (mAudioCapturedByWindow != aCapture) {
-    mAudioCapturedByWindow = aCapture;
-    AudioCaptureStreamChangeIfNeeded();
-  }
-  return NS_OK;
-}
-
 AudioTrackList*
 HTMLMediaElement::AudioTracks()
 {
@@ -7056,59 +6762,6 @@ HTMLMediaElement::NotifyAudioPlaybackChanged(AudibleChangedReasons aReason)
   }
 }
 
-bool
-HTMLMediaElement::IsAudible() const
-{
-  // Muted or the volume should not be ~0
-  if (Muted() || (std::fabs(Volume()) <= 1e-7)) {
-    return false;
-  }
-
-  // No sound can be heard during suspending.
-  if (IsSuspendedByAudioChannel()) {
-    return false;
-  }
-
-  // Silent audio track.
-  if (!mIsAudioTrackAudible) {
-    return false;
-  }
-
-  return true;
-}
-
-void
-HTMLMediaElement::MaybeNotifyMediaResumed(SuspendTypes aSuspend)
-{
-  // In fennec, we should send the notification when media is resumed from the
-  // pause-disposable which was called by media control.
-  if (mAudioChannelSuspended != nsISuspendedTypes::SUSPENDED_PAUSE_DISPOSABLE &&
-      aSuspend != nsISuspendedTypes::NONE_SUSPENDED) {
-    return;
-  }
-
-  MOZ_ASSERT(mAudioChannelAgent);
-  uint64_t windowID = mAudioChannelAgent->WindowID();
-  NS_DispatchToMainThread(NS_NewRunnableFunction([windowID]() -> void {
-    nsCOMPtr<nsIObserverService> observerService =
-      services::GetObserverService();
-    if (NS_WARN_IF(!observerService)) {
-      return;
-    }
-
-    nsCOMPtr<nsISupportsPRUint64> wrapper =
-      do_CreateInstance(NS_SUPPORTS_PRUINT64_CONTRACTID);
-    if (NS_WARN_IF(!wrapper)) {
-       return;
-    }
-
-    wrapper->SetData(windowID);
-    observerService->NotifyObservers(wrapper,
-                                     "media-playback-resumed",
-                                     u"active");
-  }));
-}
-
 bool
 HTMLMediaElement::ShouldElementBePaused()
 {
diff --git a/dom/html/HTMLMediaElement.h b/dom/html/HTMLMediaElement.h
index 600803c55305..d2f032554734 100644
--- a/dom/html/HTMLMediaElement.h
+++ b/dom/html/HTMLMediaElement.h
@@ -48,7 +48,6 @@ class MediaResource;
 class MediaDecoder;
 class VideoFrameContainer;
 namespace dom {
-class AudioChannelAgent;
 class MediaKeys;
 class TextTrack;
 class TimeRanges;
@@ -1204,9 +1203,6 @@ protected:
   // next block of audio samples) preceeding seek target.
   already_AddRefed<Promise> Seek(double aTime, SeekTarget::Type aSeekType, ErrorResult& aRv);
 
-  // A method to check if we are playing through the AudioChannel.
-  bool IsPlayingThroughTheAudioChannel() const;
-
   // Update the audio channel playing state
   void UpdateAudioChannelPlayingState(bool aForcePlaying = false);
 
@@ -1222,68 +1218,18 @@ protected:
   // Recomputes ready state and fires events as necessary based on current state.
   void UpdateReadyStateInternal();
 
-  // Notifies the audio channel agent when the element starts or stops playing.
-  void NotifyAudioChannelAgent(bool aPlaying);
-
-  // True if we create the audio channel agent successfully or we already have
-  // one. The agent is used to communicate with the AudioChannelService. eg.
-  // notify we are playing/audible and receive muted/unmuted/suspend/resume
-  // commands from AudioChannelService.
-  bool MaybeCreateAudioChannelAgent();
-
   // Determine if the element should be paused because of suspend conditions.
   bool ShouldElementBePaused();
 
   // Create or destroy the captured stream.
   void AudioCaptureStreamChange(bool aCapture);
 
-  /**
-   * We have different kinds of suspended cases,
-   * - SUSPENDED_PAUSE
-   * It's used when we temporary lost platform audio focus. MediaElement can
-   * only be resumed when we gain the audio focus again.
-   *
-   * - SUSPENDED_PAUSE_DISPOSABLE
-   * It's used when user press the pause botton on the remote media-control.
-   * MediaElement can be resumed by reomte media-control or via play().
-   *
-   * - SUSPENDED_BLOCK
-   * It's used to reduce the power comsuption, we won't play the auto-play
-   * audio/video in the page we have never visited before. MediaElement would
-   * be resumed when the page is active. See bug647429 for more details.
-   *
-   * - SUSPENDED_STOP_DISPOSABLE
-   * When we permanently lost platform audio focus, we shuold stop playing
-   * and stop the audio channel agent. MediaElement can only be restarted by
-   * play().
-   */
-  void PauseByAudioChannel(SuspendTypes aSuspend);
-  void BlockByAudioChannel();
-
-  void ResumeFromAudioChannel();
-  void ResumeFromAudioChannelPaused(SuspendTypes aSuspend);
-  void ResumeFromAudioChannelBlocked();
-
-  bool IsSuspendedByAudioChannel() const;
-  void SetAudioChannelSuspended(SuspendTypes aSuspend);
-
   // A method to check whether the media element is allowed to start playback.
   bool IsAllowedToPlay();
-  bool IsAllowedToPlayByAudioChannel();
 
   // If the network state is empty and then we would trigger DoLoad().
   void MaybeDoLoad();
 
-  // True if the tab which media element belongs to has been to foreground at
-  // least once or activated by manually clicking the unblocking tab icon.
-  bool IsTabActivated() const;
-
-  bool IsAudible() const;
-
-  // It's used for fennec only, send the notification when the user resumes the
-  // media which was paused by media control.
-  void MaybeNotifyMediaResumed(SuspendTypes aSuspend);
-
   class nsAsyncEventRunner;
   using nsGenericHTMLElement::DispatchEvent;
   // For nsAsyncEventRunner.
@@ -1504,7 +1450,6 @@ protected:
   };
 
   uint32_t mMuted;
-  SuspendTypes mAudioChannelSuspended;
 
   // True if the media statistics are currently being shown by the builtin
   // video controls
@@ -1521,19 +1466,12 @@ protected:
   // True if the sound is being captured.
   bool mAudioCaptured;
 
-  // True if the sound is being captured by the window.
-  bool mAudioCapturedByWindow;
-
   // If TRUE then the media element was actively playing before the currently
   // in progress seeking. If FALSE then the media element is either not seeking
   // or was not actively playing before the current seek. Used to decide whether
   // to raise the 'waiting' event as per 4.7.1.8 in HTML 5 specification.
   bool mPlayingBeforeSeek;
 
-  // if TRUE then the seek started while content was in active playing state
-  // if FALSE then the seek started while the content was not playing.
-  bool mPlayingThroughTheAudioChannelBeforeSeek;
-
   // True iff this element is paused because the document is inactive or has
   // been suspended by the audio channel service.
   bool mPausedForInactiveDocumentOrChannel;
@@ -1629,21 +1567,11 @@ protected:
   // Audio Channel.
   AudioChannel mAudioChannel;
 
-  // The audio channel volume
-  float mAudioChannelVolume;
-
-  // Is this media element playing?
-  bool mPlayingThroughTheAudioChannel;
-
   // Disable the video playback by track selection. This flag might not be
   // enough if we ever expand the ability of supporting multi-tracks video
   // playback.
   bool mDisableVideo;
 
-  // An agent used to join audio channel service and its life cycle would equal
-  // to media element.
-  RefPtr<AudioChannelAgent> mAudioChannelAgent;
-
   RefPtr<TextTrackManager> mTextTrackManager;
 
   RefPtr<AudioTrackList> mAudioTrackList;
@@ -1735,9 +1663,6 @@ private:
   // True if the audio track is not silent.
   bool mIsAudioTrackAudible;
 
-  // True if media element is audible for users.
-  bool mAudible;
-
   Visibility mVisibilityState;
 
   UniquePtr<ErrorSink> mErrorSink;