9 files changed, 1421 insertions, 0 deletions
diff --git a/dom/audiochannel/AudioChannelAgent.cpp b/dom/audiochannel/AudioChannelAgent.cpp
new file mode 100644
index 0000000000..286888cc78
--- /dev/null
+++ b/dom/audiochannel/AudioChannelAgent.cpp
@@ -0,0 +1,281 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "AudioChannelAgent.h"
+#include "AudioChannelService.h"
+#include "mozilla/Preferences.h"
+#include "nsContentUtils.h"
+#include "mozilla/dom/Document.h"
+#include "nsPIDOMWindow.h"
+
+using namespace mozilla::dom;
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(AudioChannelAgent)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(AudioChannelAgent)
+  tmp->Shutdown();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mWindow)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mCallback)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(AudioChannelAgent)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mWindow)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCallback)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(AudioChannelAgent)
+  NS_INTERFACE_MAP_ENTRY(nsIAudioChannelAgent)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(AudioChannelAgent)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(AudioChannelAgent)
+
+AudioChannelAgent::AudioChannelAgent()
+    : mInnerWindowID(0), mIsRegToService(false) {
+  // Init service in the begining, it can help us to know whether there is any
+  // created media component via AudioChannelService::IsServiceStarted().
+  RefPtr<AudioChannelService> service = AudioChannelService::GetOrCreate();
+}
+
+AudioChannelAgent::~AudioChannelAgent() { Shutdown(); }
+
+void AudioChannelAgent::Shutdown() {
+  if (mIsRegToService) {
+    NotifyStoppedPlaying();
+  }
+}
+
+NS_IMETHODIMP
+AudioChannelAgent::Init(mozIDOMWindow* aWindow,
+                        nsIAudioChannelAgentCallback* aCallback) {
+  return InitInternal(nsPIDOMWindowInner::From(aWindow), aCallback,
+                      /* useWeakRef = */ false);
+}
+
+NS_IMETHODIMP
+AudioChannelAgent::InitWithWeakCallback(
+    mozIDOMWindow* aWindow, nsIAudioChannelAgentCallback* aCallback) {
+  return InitInternal(nsPIDOMWindowInner::From(aWindow), aCallback,
+                      /* useWeakRef = */ true);
+}
+
+nsresult AudioChannelAgent::FindCorrectWindow(nsPIDOMWindowInner* aWindow) {
+  mWindow = aWindow->GetInProcessScriptableTop();
+  if (NS_WARN_IF(!mWindow)) {
+    return NS_OK;
+  }
+
+  // From here we do an hack for nested iframes.
+  // The system app doesn't have access to the nested iframe objects so it
+  // cannot control the volume of the agents running in nested apps. What we do
+  // here is to assign those Agents to the top scriptable window of the parent
+  // iframe (what is controlled by the system app).
+  // For doing this we go recursively back into the chain of windows until we
+  // find apps that are not the system one.
+  nsCOMPtr<nsPIDOMWindowOuter> outerParent = mWindow->GetInProcessParent();
+  if (!outerParent || outerParent == mWindow) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsPIDOMWindowInner> parent = outerParent->GetCurrentInnerWindow();
+  if (!parent) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<Document> doc = parent->GetExtantDoc();
+  if (!doc) {
+    return NS_OK;
+  }
+
+  if (nsContentUtils::IsChromeDoc(doc)) {
+    return NS_OK;
+  }
+
+  return FindCorrectWindow(parent);
+}
+
+nsresult AudioChannelAgent::InitInternal(
+    nsPIDOMWindowInner* aWindow, nsIAudioChannelAgentCallback* aCallback,
+    bool aUseWeakRef) {
+  if (NS_WARN_IF(!aWindow)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mInnerWindowID = aWindow->WindowID();
+
+  nsresult rv = FindCorrectWindow(aWindow);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (aUseWeakRef) {
+    mWeakCallback = do_GetWeakReference(aCallback);
+  } else {
+    mCallback = aCallback;
+  }
+
+  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+          ("AudioChannelAgent, InitInternal, this = %p, "
+           "owner = %p, hasCallback = %d\n",
+           this, mWindow.get(), (!!mCallback || !!mWeakCallback)));
+
+  return NS_OK;
+}
+
+void AudioChannelAgent::PullInitialUpdate() {
+  RefPtr<AudioChannelService> service = AudioChannelService::Get();
+  MOZ_ASSERT(service);
+  MOZ_ASSERT(mIsRegToService);
+
+  AudioPlaybackConfig config = service->GetMediaConfig(mWindow);
+  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+          ("AudioChannelAgent, PullInitialUpdate, this=%p, "
+           "mute=%s, volume=%f, suspend=%s, audioCapturing=%s\n",
+           this, config.mMuted ? "true" : "false", config.mVolume,
+           SuspendTypeToStr(config.mSuspend),
+           config.mCapturedAudio ? "true" : "false"));
+  WindowVolumeChanged(config.mVolume, config.mMuted);
+  WindowSuspendChanged(config.mSuspend);
+  WindowAudioCaptureChanged(InnerWindowID(), config.mCapturedAudio);
+}
+
+NS_IMETHODIMP
+AudioChannelAgent::NotifyStartedPlaying(uint8_t aAudible) {
+  RefPtr<AudioChannelService> service = AudioChannelService::GetOrCreate();
+  if (service == nullptr || mIsRegToService) {
+    return NS_ERROR_FAILURE;
+  }
+
+  MOZ_ASSERT(AudioChannelService::AudibleState::eNotAudible == 0 &&
+             AudioChannelService::AudibleState::eMaybeAudible == 1 &&
+             AudioChannelService::AudibleState::eAudible == 2);
+  service->RegisterAudioChannelAgent(
+      this, static_cast<AudioChannelService::AudibleState>(aAudible));
+
+  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+          ("AudioChannelAgent, NotifyStartedPlaying, this = %p, audible = %s\n",
+           this,
+           AudibleStateToStr(
+               static_cast<AudioChannelService::AudibleState>(aAudible))));
+
+  mIsRegToService = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AudioChannelAgent::NotifyStoppedPlaying() {
+  if (!mIsRegToService) {
+    return NS_ERROR_FAILURE;
+  }
+
+  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+          ("AudioChannelAgent, NotifyStoppedPlaying, this = %p\n", this));
+
+  RefPtr<AudioChannelService> service = AudioChannelService::GetOrCreate();
+  if (service) {
+    service->UnregisterAudioChannelAgent(this);
+  }
+
+  mIsRegToService = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+AudioChannelAgent::NotifyStartedAudible(uint8_t aAudible, uint32_t aReason) {
+  MOZ_LOG(
+      AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+      ("AudioChannelAgent, NotifyStartedAudible, this = %p, "
+       "audible = %s, reason = %s\n",
+       this,
+       AudibleStateToStr(
+           static_cast<AudioChannelService::AudibleState>(aAudible)),
+       AudibleChangedReasonToStr(
+           static_cast<AudioChannelService::AudibleChangedReasons>(aReason))));
+
+  RefPtr<AudioChannelService> service = AudioChannelService::GetOrCreate();
+  if (NS_WARN_IF(!service)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  service->AudioAudibleChanged(
+      this, static_cast<AudioChannelService::AudibleState>(aAudible),
+      static_cast<AudioChannelService::AudibleChangedReasons>(aReason));
+  return NS_OK;
+}
+
+already_AddRefed<nsIAudioChannelAgentCallback>
+AudioChannelAgent::GetCallback() {
+  nsCOMPtr<nsIAudioChannelAgentCallback> callback = mCallback;
+  if (!callback) {
+    callback = do_QueryReferent(mWeakCallback);
+  }
+  return callback.forget();
+}
+
+void AudioChannelAgent::WindowVolumeChanged(float aVolume, bool aMuted) {
+  nsCOMPtr<nsIAudioChannelAgentCallback> callback = GetCallback();
+  if (!callback) {
+    return;
+  }
+
+  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+          ("AudioChannelAgent, WindowVolumeChanged, this = %p, mute = %s, "
+           "volume = %f\n",
+           this, aMuted ? "true" : "false", aVolume));
+  callback->WindowVolumeChanged(aVolume, aMuted);
+}
+
+void AudioChannelAgent::WindowSuspendChanged(nsSuspendedTypes aSuspend) {
+  nsCOMPtr<nsIAudioChannelAgentCallback> callback = GetCallback();
+  if (!callback) {
+    return;
+  }
+
+  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+          ("AudioChannelAgent, WindowSuspendChanged, this = %p, "
+           "suspended = %s\n",
+           this, SuspendTypeToStr(aSuspend)));
+  callback->WindowSuspendChanged(aSuspend);
+}
+
+AudioPlaybackConfig AudioChannelAgent::GetMediaConfig() const {
+  RefPtr<AudioChannelService> service = AudioChannelService::GetOrCreate();
+  AudioPlaybackConfig config(1.0, false, nsISuspendedTypes::NONE_SUSPENDED);
+  if (service) {
+    config = service->GetMediaConfig(mWindow);
+  }
+  return config;
+}
+
+uint64_t AudioChannelAgent::WindowID() const {
+  return mWindow ? mWindow->WindowID() : 0;
+}
+
+uint64_t AudioChannelAgent::InnerWindowID() const { return mInnerWindowID; }
+
+void AudioChannelAgent::WindowAudioCaptureChanged(uint64_t aInnerWindowID,
+                                                  bool aCapture) {
+  if (aInnerWindowID != mInnerWindowID) {
+    return;
+  }
+
+  nsCOMPtr<nsIAudioChannelAgentCallback> callback = GetCallback();
+  if (!callback) {
+    return;
+  }
+
+  MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+          ("AudioChannelAgent, WindowAudioCaptureChanged, this = %p, "
+           "capture = %d\n",
+           this, aCapture));
+
+  callback->WindowAudioCaptureChanged(aCapture);
+}
+
+bool AudioChannelAgent::IsWindowAudioCapturingEnabled() const {
+  return GetMediaConfig().mCapturedAudio;
+}
+
+bool AudioChannelAgent::IsPlayingStarted() const { return mIsRegToService; }
diff --git a/dom/audiochannel/AudioChannelAgent.h b/dom/audiochannel/AudioChannelAgent.h
new file mode 100644
index 0000000000..9682219844
--- /dev/null
+++ b/dom/audiochannel/AudioChannelAgent.h
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_audio_channel_agent_h__
+#define mozilla_dom_audio_channel_agent_h__
+
+#include "nsIAudioChannelAgent.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsCOMPtr.h"
+#include "nsIWeakReferenceUtils.h"
+
+class nsPIDOMWindowInner;
+class nsPIDOMWindowOuter;
+
+namespace mozilla::dom {
+
+class AudioPlaybackConfig;
+
+/* Header file */
+class AudioChannelAgent : public nsIAudioChannelAgent {
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_NSIAUDIOCHANNELAGENT
+
+  NS_DECL_CYCLE_COLLECTION_CLASS(AudioChannelAgent)
+
+  AudioChannelAgent();
+
+  // nsIAudioChannelAgentCallback MUST call this function after calling
+  // NotifyStartedPlaying() to require the initial update for
+  // volume/suspend/audio-capturing which might set before starting the agent.
+  // Ex. starting the agent in a tab which has been muted before, so the agent
+  // should apply mute state to its callback.
+  void PullInitialUpdate();
+
+  uint64_t WindowID() const;
+
+  bool IsWindowAudioCapturingEnabled() const;
+  bool IsPlayingStarted() const;
+
+ private:
+  virtual ~AudioChannelAgent();
+
+  friend class AudioChannelService;
+  void WindowVolumeChanged(float aVolume, bool aMuted);
+  void WindowSuspendChanged(nsSuspendedTypes aSuspend);
+  void WindowAudioCaptureChanged(uint64_t aInnerWindowID, bool aCapture);
+
+  nsPIDOMWindowOuter* Window() const { return mWindow; }
+  uint64_t InnerWindowID() const;
+  AudioPlaybackConfig GetMediaConfig() const;
+
+  // Returns mCallback if that's non-null, or otherwise tries to get an
+  // nsIAudioChannelAgentCallback out of mWeakCallback.
+  already_AddRefed<nsIAudioChannelAgentCallback> GetCallback();
+
+  nsresult InitInternal(nsPIDOMWindowInner* aWindow,
+                        nsIAudioChannelAgentCallback* aCallback,
+                        bool aUseWeakRef);
+
+  void Shutdown();
+
+  nsresult FindCorrectWindow(nsPIDOMWindowInner* aWindow);
+
+  nsCOMPtr<nsPIDOMWindowOuter> mWindow;
+  nsCOMPtr<nsIAudioChannelAgentCallback> mCallback;
+
+  nsWeakPtr mWeakCallback;
+
+  uint64_t mInnerWindowID;
+  bool mIsRegToService;
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/audiochannel/AudioChannelService.cpp b/dom/audiochannel/AudioChannelService.cpp
new file mode 100644
index 0000000000..a29bab62ef
--- /dev/null
+++ b/dom/audiochannel/AudioChannelService.cpp
@@ -0,0 +1,625 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "AudioChannelService.h"
+
+#include "base/basictypes.h"
+
+#include "mozilla/Services.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/Unused.h"
+#include "mozilla/dom/Document.h"
+
+#include "nsContentUtils.h"
+#include "nsISupportsPrimitives.h"
+#include "nsThreadUtils.h"
+#include "nsHashPropertyBag.h"
+#include "nsComponentManagerUtils.h"
+#include "nsGlobalWindow.h"
+#include "nsPIDOMWindow.h"
+#include "nsServiceManagerUtils.h"
+
+#include "mozilla/Preferences.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+mozilla::LazyLogModule gAudioChannelLog("AudioChannel");
+
+namespace {
+
+bool sXPCOMShuttingDown = false;
+
+class AudioPlaybackRunnable final : public Runnable {
+ public:
+  AudioPlaybackRunnable(nsPIDOMWindowOuter* aWindow, bool aActive,
+                        AudioChannelService::AudibleChangedReasons aReason)
+      : mozilla::Runnable("AudioPlaybackRunnable"),
+        mWindow(aWindow),
+        mActive(aActive),
+        mReason(aReason) {}
+
+  NS_IMETHOD Run() override {
+    nsCOMPtr<nsIObserverService> observerService =
+        services::GetObserverService();
+    if (NS_WARN_IF(!observerService)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    nsAutoString state;
+    GetActiveState(state);
+
+    observerService->NotifyObservers(ToSupports(mWindow), "audio-playback",
+                                     state.get());
+
+    MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
+            ("AudioPlaybackRunnable, active = %s, reason = %s\n",
+             mActive ? "true" : "false", AudibleChangedReasonToStr(mReason)));
+
+    return NS_OK;
+  }
+
+ private:
+  void GetActiveState(nsAString& aState) {
+    if (mActive) {
+      aState.AssignLiteral("active");
+    } else {
+      if (mReason ==
+          AudioChannelService::AudibleChangedReasons::ePauseStateChanged) {
+        aState.AssignLiteral("inactive-pause");
+      } else {
+        aState.AssignLiteral("inactive-nonaudible");
+      }
+    }
+  }
+
+  nsCOMPtr<nsPIDOMWindowOuter> mWindow;
+  bool mActive;
+  AudioChannelService::AudibleChangedReasons mReason;
+};
+
+}  // anonymous namespace
+
+namespace mozilla::dom {
+
+const char* SuspendTypeToStr(const nsSuspendedTypes& aSuspend) {
+  MOZ_ASSERT(aSuspend == nsISuspendedTypes::NONE_SUSPENDED ||
+             aSuspend == nsISuspendedTypes::SUSPENDED_BLOCK);
+
+  switch (aSuspend) {
+    case nsISuspendedTypes::NONE_SUSPENDED:
+      return "none";
+    case nsISuspendedTypes::SUSPENDED_BLOCK:
+      return "block";
+    default:
+      return "unknown";
+  }
+}
+
+const char* AudibleStateToStr(
+    const AudioChannelService::AudibleState& aAudible) {
+  MOZ_ASSERT(aAudible == AudioChannelService::AudibleState::eNotAudible ||
+             aAudible == AudioChannelService::AudibleState::eMaybeAudible ||
+             aAudible == AudioChannelService::AudibleState::eAudible);
+
+  switch (aAudible) {
+    case AudioChannelService::AudibleState::eNotAudible:
+      return "not-audible";
+    case AudioChannelService::AudibleState::eMaybeAudible:
+      return "maybe-audible";
+    case AudioChannelService::AudibleState::eAudible:
+      return "audible";
+    default:
+      return "unknown";
+  }
+}
+
+const char* AudibleChangedReasonToStr(
+    const AudioChannelService::AudibleChangedReasons& aReason) {
+  MOZ_ASSERT(
+      aReason == AudioChannelService::AudibleChangedReasons::eVolumeChanged ||
+      aReason ==
+          AudioChannelService::AudibleChangedReasons::eDataAudibleChanged ||
+      aReason ==
+          AudioChannelService::AudibleChangedReasons::ePauseStateChanged);
+
+  switch (aReason) {
+    case AudioChannelService::AudibleChangedReasons::eVolumeChanged:
+      return "volume";
+    case AudioChannelService::AudibleChangedReasons::eDataAudibleChanged:
+      return "data-audible";
+    case AudioChannelService::AudibleChangedReasons::ePauseStateChanged:
+      return "pause-state";
+    default:
+      return "unknown";
+  }
+}
+
+StaticRefPtr<AudioChannelService> gAudioChannelService;
+
+/* static */
+void AudioChannelService::CreateServiceIfNeeded() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!gAudioChannelService) {
+    gAudioChannelService = new AudioChannelService();
+  }
+}
+
+/* static */
+already_AddRefed<AudioChannelService> AudioChannelService::GetOrCreate() {
+  if (sXPCOMShuttingDown) {
+    return nullptr;
+  }
+
+  CreateServiceIfNeeded();
+  RefPtr<AudioChannelService> service = gAudioChannelService.get();
+  return service.forget();
+}
+
+/* static */
+already_AddRefed<AudioChannelService> AudioChannelService::Get() {
+  if (sXPCOMShuttingDown) {
+    return nullptr;
+  }
+
+  RefPtr<AudioChannelService> service = gAudioChannelService.get();
+  return service.forget();
+}
+
+/* static */
+LogModule* AudioChannelService::GetAudioChannelLog() {
+  return gAudioChannelLog;
+}
+
+/* static */
+void AudioChannelService::Shutdown() {
+  if (gAudioChannelService) {
+    nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+    if (obs) {
+      obs->RemoveObserver(gAudioChannelService, "xpcom-shutdown");
+      obs->RemoveObserver(gAudioChannelService, "outer-window-destroyed");
+    }
+
+    gAudioChannelService->mWindows.Clear();
+
+    gAudioChannelService = nullptr;
+  }
+}
+
+NS_INTERFACE_MAP_BEGIN(AudioChannelService)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIObserver)
+  NS_INTERFACE_MAP_ENTRY(nsIObserver)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_ADDREF(AudioChannelService)
+NS_IMPL_RELEASE(AudioChannelService)
+
+AudioChannelService::AudioChannelService() {
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (obs) {
+    obs->AddObserver(this, "xpcom-shutdown", false);
+    obs->AddObserver(this, "outer-window-destroyed", false);
+  }
+}
+
+AudioChannelService::~AudioChannelService() = default;
+
+void AudioChannelService::RegisterAudioChannelAgent(AudioChannelAgent* aAgent,
+                                                    AudibleState aAudible) {
+  MOZ_ASSERT(aAgent);
+
+  uint64_t windowID = aAgent->WindowID();
+  AudioChannelWindow* winData = GetWindowData(windowID);
+  if (!winData) {
+    winData = new AudioChannelWindow(windowID);
+    mWindows.AppendElement(WrapUnique(winData));
+  }
+
+  // To make sure agent would be alive because AppendAgent() would trigger the
+  // callback function of AudioChannelAgentOwner that means the agent might be
+  // released in their callback.
+  RefPtr<AudioChannelAgent> kungFuDeathGrip(aAgent);
+  winData->AppendAgent(aAgent, aAudible);
+}
+
+void AudioChannelService::UnregisterAudioChannelAgent(
+    AudioChannelAgent* aAgent) {
+  MOZ_ASSERT(aAgent);
+
+  AudioChannelWindow* winData = GetWindowData(aAgent->WindowID());
+  if (!winData) {
+    return;
+  }
+
+  // To make sure agent would be alive because AppendAgent() would trigger the
+  // callback function of AudioChannelAgentOwner that means the agent might be
+  // released in their callback.
+  RefPtr<AudioChannelAgent> kungFuDeathGrip(aAgent);
+  winData->RemoveAgent(aAgent);
+}
+
+AudioPlaybackConfig AudioChannelService::GetMediaConfig(
+    nsPIDOMWindowOuter* aWindow) const {
+  AudioPlaybackConfig config(1.0, false, nsISuspendedTypes::NONE_SUSPENDED);
+
+  if (!aWindow) {
+    config.mVolume = 0.0;
+    config.mMuted = true;
+    config.mSuspend = nsISuspendedTypes::SUSPENDED_BLOCK;
+    return config;
+  }
+
+  AudioChannelWindow* winData = nullptr;
+  nsCOMPtr<nsPIDOMWindowOuter> window = aWindow;
+
+  // The volume must be calculated based on the window hierarchy. Here we go up
+  // to the top window and we calculate the volume and the muted flag.
+  do {
+    winData = GetWindowData(window->WindowID());
+    if (winData) {
+      config.mVolume *= winData->mConfig.mVolume;
+      config.mMuted = config.mMuted || winData->mConfig.mMuted;
+      config.mCapturedAudio = winData->mIsAudioCaptured;
+    }
+
+    config.mMuted = config.mMuted || window->GetAudioMuted();
+    if (window->ShouldDelayMediaFromStart()) {
+      config.mSuspend = nsISuspendedTypes::SUSPENDED_BLOCK;
+    }
+
+    nsCOMPtr<nsPIDOMWindowOuter> win =
+        window->GetInProcessScriptableParentOrNull();
+    if (!win) {
+      break;
+    }
+
+    window = win;
+
+    // If there is no parent, or we are the toplevel we don't continue.
+  } while (window && window != aWindow);
+
+  return config;
+}
+
+void AudioChannelService::AudioAudibleChanged(AudioChannelAgent* aAgent,
+                                              AudibleState aAudible,
+                                              AudibleChangedReasons aReason) {
+  MOZ_ASSERT(aAgent);
+
+  uint64_t windowID = aAgent->WindowID();
+  AudioChannelWindow* winData = GetWindowData(windowID);
+  if (winData) {
+    winData->AudioAudibleChanged(aAgent, aAudible, aReason);
+  }
+}
+
+NS_IMETHODIMP
+AudioChannelService::Observe(nsISupports* aSubject, const char* aTopic,
+                             const char16_t* aData) {
+  if (!strcmp(aTopic, "xpcom-shutdown")) {
+    sXPCOMShuttingDown = true;
+    Shutdown();
+  } else if (!strcmp(aTopic, "outer-window-destroyed")) {
+    nsCOMPtr<nsISupportsPRUint64> wrapper = do_QueryInterface(aSubject);
+    NS_ENSURE_TRUE(wrapper, NS_ERROR_FAILURE);
+
+    uint64_t outerID;
+    nsresult rv = wrapper->GetData(&outerID);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    UniquePtr<AudioChannelWindow> winData;
+    {
+      nsTObserverArray<UniquePtr<AudioChannelWindow>>::ForwardIterator iter(
+          mWindows);
+      while (iter.HasMore()) {
+        auto& next = iter.GetNext();
+        if (next->mWindowID == outerID) {
+          winData = std::move(next);
+          iter.Remove();
+          break;
+        }
+      }
+    }
+
+    if (winData) {
+      for (AudioChannelAgent* agent : winData->mAgents.ForwardRange()) {
+        agent->WindowVolumeChanged(winData->mConfig.mVolume,
+                                   winData->mConfig.mMuted);
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+void AudioChannelService::RefreshAgents(
+    nsPIDOMWindowOuter* aWindow,
+    const std::function<void(AudioChannelAgent*)>& aFunc) {
+  MOZ_ASSERT(aWindow);
+
+  nsCOMPtr<nsPIDOMWindowOuter> topWindow = aWindow->GetInProcessScriptableTop();
+  if (!topWindow) {
+    return;
+  }
+
+  AudioChannelWindow* winData = GetWindowData(topWindow->WindowID());
+  if (!winData) {
+    return;
+  }
+
+  for (AudioChannelAgent* agent : winData->mAgents.ForwardRange()) {
+    aFunc(agent);
+  }
+}
+
+void AudioChannelService::RefreshAgentsVolume(nsPIDOMWindowOuter* aWindow,
+                                              float aVolume, bool aMuted) {
+  RefreshAgents(aWindow, [aVolume, aMuted](AudioChannelAgent* agent) {
+    agent->WindowVolumeChanged(aVolume, aMuted);
+  });
+}
+
+void AudioChannelService::RefreshAgentsSuspend(nsPIDOMWindowOuter* aWindow,
+                                               nsSuspendedTypes aSuspend) {
+  RefreshAgents(aWindow, [aSuspend](AudioChannelAgent* agent) {
+    agent->WindowSuspendChanged(aSuspend);
+  });
+}
+
+void AudioChannelService::SetWindowAudioCaptured(nsPIDOMWindowOuter* aWindow,
+                                                 uint64_t aInnerWindowID,
+                                                 bool aCapture) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aWindow);
+
+  MOZ_LOG(GetAudioChannelLog(), LogLevel::Debug,
+          ("AudioChannelService, SetWindowAudioCaptured, window = %p, "
+           "aCapture = %d\n",
+           aWindow, aCapture));
+
+  nsCOMPtr<nsPIDOMWindowOuter> topWindow = aWindow->GetInProcessScriptableTop();
+  if (!topWindow) {
+    return;
+  }
+
+  AudioChannelWindow* winData = GetWindowData(topWindow->WindowID());
+
+  // This can happen, but only during shutdown, because the the outer window
+  // changes ScriptableTop, so that its ID is different.
+  // In this case either we are capturing, and it's too late because the window
+  // has been closed anyways, or we are un-capturing, and everything has already
+  // been cleaned up by the HTMLMediaElements or the AudioContexts.
+  if (!winData) {
+    return;
+  }
+
+  if (aCapture != winData->mIsAudioCaptured) {
+    winData->mIsAudioCaptured = aCapture;
+    for (AudioChannelAgent* agent : winData->mAgents.ForwardRange()) {
+      agent->WindowAudioCaptureChanged(aInnerWindowID, aCapture);
+    }
+  }
+}
+
+AudioChannelService::AudioChannelWindow*
+AudioChannelService::GetOrCreateWindowData(nsPIDOMWindowOuter* aWindow) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aWindow);
+
+  AudioChannelWindow* winData = GetWindowData(aWindow->WindowID());
+  if (!winData) {
+    winData = new AudioChannelWindow(aWindow->WindowID());
+    mWindows.AppendElement(WrapUnique(winData));
+  }
+
+  return winData;
+}
+
+AudioChannelService::AudioChannelWindow* AudioChannelService::GetWindowData(
+    uint64_t aWindowID) const {
+  const auto [begin, end] = mWindows.NonObservingRange();
+  const auto foundIt = std::find_if(begin, end, [aWindowID](const auto& next) {
+    return next->mWindowID == aWindowID;
+  });
+  return foundIt != end ? foundIt->get() : nullptr;
+}
+
+bool AudioChannelService::IsWindowActive(nsPIDOMWindowOuter* aWindow) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  auto* window = nsPIDOMWindowOuter::From(aWindow)->GetInProcessScriptableTop();
+  if (!window) {
+    return false;
+  }
+
+  AudioChannelWindow* winData = GetWindowData(window->WindowID());
+  if (!winData) {
+    return false;
+  }
+
+  return !winData->mAudibleAgents.IsEmpty();
+}
+
+void AudioChannelService::NotifyResumingDelayedMedia(
+    nsPIDOMWindowOuter* aWindow) {
+  MOZ_ASSERT(aWindow);
+
+  nsCOMPtr<nsPIDOMWindowOuter> topWindow = aWindow->GetInProcessScriptableTop();
+  if (!topWindow) {
+    return;
+  }
+
+  AudioChannelWindow* winData = GetWindowData(topWindow->WindowID());
+  if (!winData) {
+    return;
+  }
+
+  winData->NotifyMediaBlockStop(aWindow);
+  RefreshAgentsSuspend(aWindow, nsISuspendedTypes::NONE_SUSPENDED);
+}
+
+void AudioChannelService::AudioChannelWindow::AppendAgent(
+    AudioChannelAgent* aAgent, AudibleState aAudible) {
+  MOZ_ASSERT(aAgent);
+
+  AppendAgentAndIncreaseAgentsNum(aAgent);
+  AudioAudibleChanged(aAgent, aAudible,
+                      AudibleChangedReasons::eDataAudibleChanged);
+}
+
+void AudioChannelService::AudioChannelWindow::RemoveAgent(
+    AudioChannelAgent* aAgent) {
+  MOZ_ASSERT(aAgent);
+
+  RemoveAgentAndReduceAgentsNum(aAgent);
+  AudioAudibleChanged(aAgent, AudibleState::eNotAudible,
+                      AudibleChangedReasons::ePauseStateChanged);
+}
+
+void AudioChannelService::AudioChannelWindow::NotifyMediaBlockStop(
+    nsPIDOMWindowOuter* aWindow) {
+  if (mShouldSendActiveMediaBlockStopEvent) {
+    mShouldSendActiveMediaBlockStopEvent = false;
+    nsCOMPtr<nsPIDOMWindowOuter> window = aWindow;
+    NS_DispatchToCurrentThread(NS_NewRunnableFunction(
+        "dom::AudioChannelService::AudioChannelWindow::NotifyMediaBlockStop",
+        [window]() -> void {
+          nsCOMPtr<nsIObserverService> observerService =
+              services::GetObserverService();
+          if (NS_WARN_IF(!observerService)) {
+            return;
+          }
+
+          observerService->NotifyObservers(ToSupports(window), "audio-playback",
+                                           u"activeMediaBlockStop");
+        }));
+  }
+}
+
+void AudioChannelService::AudioChannelWindow::AppendAgentAndIncreaseAgentsNum(
+    AudioChannelAgent* aAgent) {
+  MOZ_ASSERT(aAgent);
+  MOZ_ASSERT(!mAgents.Contains(aAgent));
+
+  mAgents.AppendElement(aAgent);
+
+  ++mConfig.mNumberOfAgents;
+}
+
+void AudioChannelService::AudioChannelWindow::RemoveAgentAndReduceAgentsNum(
+    AudioChannelAgent* aAgent) {
+  MOZ_ASSERT(aAgent);
+  MOZ_ASSERT(mAgents.Contains(aAgent));
+
+  mAgents.RemoveElement(aAgent);
+
+  MOZ_ASSERT(mConfig.mNumberOfAgents > 0);
+  --mConfig.mNumberOfAgents;
+}
+
+void AudioChannelService::AudioChannelWindow::AudioAudibleChanged(
+    AudioChannelAgent* aAgent, AudibleState aAudible,
+    AudibleChangedReasons aReason) {
+  MOZ_ASSERT(aAgent);
+
+  if (aAudible == AudibleState::eAudible) {
+    AppendAudibleAgentIfNotContained(aAgent, aReason);
+  } else {
+    RemoveAudibleAgentIfContained(aAgent, aReason);
+  }
+
+  if (aAudible != AudibleState::eNotAudible) {
+    MaybeNotifyMediaBlockStart(aAgent);
+  }
+}
+
+void AudioChannelService::AudioChannelWindow::AppendAudibleAgentIfNotContained(
+    AudioChannelAgent* aAgent, AudibleChangedReasons aReason) {
+  MOZ_ASSERT(aAgent);
+  MOZ_ASSERT(mAgents.Contains(aAgent));
+
+  if (!mAudibleAgents.Contains(aAgent)) {
+    mAudibleAgents.AppendElement(aAgent);
+    if (IsFirstAudibleAgent()) {
+      NotifyAudioAudibleChanged(aAgent->Window(), AudibleState::eAudible,
+                                aReason);
+    }
+  }
+}
+
+void AudioChannelService::AudioChannelWindow::RemoveAudibleAgentIfContained(
+    AudioChannelAgent* aAgent, AudibleChangedReasons aReason) {
+  MOZ_ASSERT(aAgent);
+
+  if (mAudibleAgents.Contains(aAgent)) {
+    mAudibleAgents.RemoveElement(aAgent);
+    if (IsLastAudibleAgent()) {
+      NotifyAudioAudibleChanged(aAgent->Window(), AudibleState::eNotAudible,
+                                aReason);
+    }
+  }
+}
+
+bool AudioChannelService::AudioChannelWindow::IsFirstAudibleAgent() const {
+  return (mAudibleAgents.Length() == 1);
+}
+
+bool AudioChannelService::AudioChannelWindow::IsLastAudibleAgent() const {
+  return mAudibleAgents.IsEmpty();
+}
+
+void AudioChannelService::AudioChannelWindow::NotifyAudioAudibleChanged(
+    nsPIDOMWindowOuter* aWindow, AudibleState aAudible,
+    AudibleChangedReasons aReason) {
+  RefPtr<AudioPlaybackRunnable> runnable = new AudioPlaybackRunnable(
+      aWindow, aAudible == AudibleState::eAudible, aReason);
+  DebugOnly<nsresult> rv = NS_DispatchToCurrentThread(runnable);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToCurrentThread failed");
+}
+
+void AudioChannelService::AudioChannelWindow::MaybeNotifyMediaBlockStart(
+    AudioChannelAgent* aAgent) {
+  nsCOMPtr<nsPIDOMWindowOuter> window = aAgent->Window();
+  if (!window) {
+    return;
+  }
+
+  nsCOMPtr<nsPIDOMWindowInner> inner = window->GetCurrentInnerWindow();
+  if (!inner) {
+    return;
+  }
+
+  nsCOMPtr<Document> doc = inner->GetExtantDoc();
+  if (!doc) {
+    return;
+  }
+
+  if (!window->ShouldDelayMediaFromStart() || !doc->Hidden()) {
+    return;
+  }
+
+  if (!mShouldSendActiveMediaBlockStopEvent) {
+    mShouldSendActiveMediaBlockStopEvent = true;
+    NS_DispatchToCurrentThread(NS_NewRunnableFunction(
+        "dom::AudioChannelService::AudioChannelWindow::"
+        "MaybeNotifyMediaBlockStart",
+        [window]() -> void {
+          nsCOMPtr<nsIObserverService> observerService =
+              services::GetObserverService();
+          if (NS_WARN_IF(!observerService)) {
+            return;
+          }
+
+          observerService->NotifyObservers(ToSupports(window), "audio-playback",
+                                           u"activeMediaBlockStart");
+        }));
+  }
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/audiochannel/AudioChannelService.h b/dom/audiochannel/AudioChannelService.h
new file mode 100644
index 0000000000..bf7fa387e2
--- /dev/null
+++ b/dom/audiochannel/AudioChannelService.h
@@ -0,0 +1,245 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_audiochannelservice_h__
+#define mozilla_dom_audiochannelservice_h__
+
+#include "nsIObserver.h"
+#include "nsTObserverArray.h"
+#include "nsTArray.h"
+
+#include "AudioChannelAgent.h"
+#include "nsAttrValue.h"
+#include "mozilla/Logging.h"
+#include "mozilla/UniquePtr.h"
+
+#include <functional>
+
+class nsPIDOMWindowOuter;
+struct PRLogModuleInfo;
+
+namespace mozilla::dom {
+
+class AudioPlaybackConfig {
+ public:
+  AudioPlaybackConfig()
+      : mVolume(1.0),
+        mMuted(false),
+        mSuspend(nsISuspendedTypes::NONE_SUSPENDED),
+        mNumberOfAgents(0) {}
+
+  AudioPlaybackConfig(float aVolume, bool aMuted, uint32_t aSuspended)
+      : mVolume(aVolume),
+        mMuted(aMuted),
+        mSuspend(aSuspended),
+        mNumberOfAgents(0) {}
+
+  float mVolume;
+  bool mMuted;
+  uint32_t mSuspend;
+  bool mCapturedAudio = false;
+  uint32_t mNumberOfAgents;
+};
+
+class AudioChannelService final : public nsIObserver {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+  /**
+   * We use `AudibleState` to represent the audible state of an owner of audio
+   * channel agent. Those information in AudioChannelWindow could help us to
+   * determine if a tab is being audible or not, in order to tell Chrome JS to
+   * show the sound indicator or delayed autoplay icon on the tab bar.
+   *
+   * - Sound indicator
+   * When a tab is playing sound, we would show the sound indicator on tab bar
+   * to tell users that this tab is producing sound now. In addition, the sound
+   * indicator also give users an ablility to mute or unmute tab.
+   *
+   * When an AudioChannelWindow first contains an agent with state `eAudible`,
+   * or an AudioChannelWindow losts its last agent with state `eAudible`, we
+   * would notify Chrome JS about those changes, to tell them that a tab has
+   * been being audible or not, in order to display or remove the indicator for
+   * a corresponding tab.
+   *
+   * - Delayed autoplay icon (Play Tab icon)
+   * When we enable delaying autoplay, which is to postpone the autoplay media
+   * for unvisited tab until it first goes to foreground, or user click the
+   * play tab icon to resume the delayed media.
+   *
+   * When an AudioChannelWindow first contains an agent with state `eAudible` or
+   * `eMaybeAudible`, we would notify Chrome JS about this change, in order to
+   * show the delayed autoplay tab icon to user, which is used to notice user
+   * there is a media being delayed starting, and then user can click the play
+   * tab icon to resume the start of media, or visit that tab to resume delayed
+   * media automatically.
+   *
+   * According to our UX design, we don't show this icon for inaudible media.
+   * The reason of showing the icon for a tab, where the agent starts with state
+   * `eMaybeAudible`, is because some video might be silent in the beginning
+   * but would soon become audible later.
+   *
+   * ---------------------------------------------------------------------------
+   *
+   * eNotAudible : agent is not audible
+   * eMaybeAudible : agent is not audible now, but it might be audible later
+   * eAudible : agent is audible now
+   */
+  enum AudibleState : uint8_t {
+    eNotAudible = 0,
+    eMaybeAudible = 1,
+    eAudible = 2
+  };
+
+  enum AudioCaptureState : bool { eCapturing = true, eNotCapturing = false };
+
+  enum AudibleChangedReasons : uint32_t {
+    eVolumeChanged = 0,
+    eDataAudibleChanged = 1,
+    ePauseStateChanged = 2
+  };
+
+  /**
+   * Returns the AudioChannelServce singleton.
+   * If AudioChannelService doesn't exist, create and return new one.
+   * Only to be called from main thread.
+   */
+  static already_AddRefed<AudioChannelService> GetOrCreate();
+
+  /**
+   * Returns the AudioChannelService singleton if one exists.
+   * If AudioChannelService doesn't exist, returns null.
+   */
+  static already_AddRefed<AudioChannelService> Get();
+
+  static LogModule* GetAudioChannelLog();
+
+  static bool IsEnableAudioCompeting();
+
+  /**
+   * Any audio channel agent that starts playing should register itself to
+   * this service, sharing the AudioChannel.
+   */
+  void RegisterAudioChannelAgent(AudioChannelAgent* aAgent,
+                                 AudibleState aAudible);
+
+  /**
+   * Any audio channel agent that stops playing should unregister itself to
+   * this service.
+   */
+  void UnregisterAudioChannelAgent(AudioChannelAgent* aAgent);
+
+  /**
+   * Return the state to indicate this audioChannel for his window should keep
+   * playing/muted/suspended.
+   */
+  AudioPlaybackConfig GetMediaConfig(nsPIDOMWindowOuter* aWindow) const;
+
+  /**
+   * Called this method when the audible state of the audio playback changed,
+   * it would dispatch the playback event to observers which want to know the
+   * actual audible state of the window.
+   */
+  void AudioAudibleChanged(AudioChannelAgent* aAgent, AudibleState aAudible,
+                           AudibleChangedReasons aReason);
+
+  bool IsWindowActive(nsPIDOMWindowOuter* aWindow);
+
+  void RefreshAgentsVolume(nsPIDOMWindowOuter* aWindow, float aVolume,
+                           bool aMuted);
+
+  // This method needs to know the inner window that wants to capture audio. We
+  // group agents per top outer window, but we can have multiple innerWindow per
+  // top outerWindow (subiframes, etc.) and we have to identify all the agents
+  // just for a particular innerWindow.
+  void SetWindowAudioCaptured(nsPIDOMWindowOuter* aWindow,
+                              uint64_t aInnerWindowID, bool aCapture);
+
+  void NotifyResumingDelayedMedia(nsPIDOMWindowOuter* aWindow);
+
+ private:
+  AudioChannelService();
+  ~AudioChannelService();
+
+  void RefreshAgents(nsPIDOMWindowOuter* aWindow,
+                     const std::function<void(AudioChannelAgent*)>& aFunc);
+
+  void RefreshAgentsSuspend(nsPIDOMWindowOuter* aWindow,
+                            nsSuspendedTypes aSuspend);
+
+  static void CreateServiceIfNeeded();
+
+  /**
+   * Shutdown the singleton.
+   */
+  static void Shutdown();
+
+  void RefreshAgentsAudioFocusChanged(AudioChannelAgent* aAgent);
+
+  class AudioChannelWindow final {
+   public:
+    explicit AudioChannelWindow(uint64_t aWindowID)
+        : mWindowID(aWindowID),
+          mIsAudioCaptured(false),
+          mShouldSendActiveMediaBlockStopEvent(false) {}
+
+    void AudioAudibleChanged(AudioChannelAgent* aAgent, AudibleState aAudible,
+                             AudibleChangedReasons aReason);
+
+    void AppendAgent(AudioChannelAgent* aAgent, AudibleState aAudible);
+    void RemoveAgent(AudioChannelAgent* aAgent);
+
+    void NotifyMediaBlockStop(nsPIDOMWindowOuter* aWindow);
+
+    uint64_t mWindowID;
+    bool mIsAudioCaptured;
+    AudioPlaybackConfig mConfig;
+
+    // Raw pointer because the AudioChannelAgent must unregister itself.
+    nsTObserverArray<AudioChannelAgent*> mAgents;
+    nsTObserverArray<AudioChannelAgent*> mAudibleAgents;
+
+    // If we've dispatched "activeMediaBlockStart" event, we must dispatch
+    // another event "activeMediablockStop" when the window is resumed from
+    // suspend-block.
+    bool mShouldSendActiveMediaBlockStopEvent;
+
+   private:
+    void AppendAudibleAgentIfNotContained(AudioChannelAgent* aAgent,
+                                          AudibleChangedReasons aReason);
+    void RemoveAudibleAgentIfContained(AudioChannelAgent* aAgent,
+                                       AudibleChangedReasons aReason);
+
+    void AppendAgentAndIncreaseAgentsNum(AudioChannelAgent* aAgent);
+    void RemoveAgentAndReduceAgentsNum(AudioChannelAgent* aAgent);
+
+    bool IsFirstAudibleAgent() const;
+    bool IsLastAudibleAgent() const;
+
+    void NotifyAudioAudibleChanged(nsPIDOMWindowOuter* aWindow,
+                                   AudibleState aAudible,
+                                   AudibleChangedReasons aReason);
+
+    void MaybeNotifyMediaBlockStart(AudioChannelAgent* aAgent);
+  };
+
+  AudioChannelWindow* GetOrCreateWindowData(nsPIDOMWindowOuter* aWindow);
+
+  AudioChannelWindow* GetWindowData(uint64_t aWindowID) const;
+
+  nsTObserverArray<UniquePtr<AudioChannelWindow>> mWindows;
+};
+
+const char* SuspendTypeToStr(const nsSuspendedTypes& aSuspend);
+const char* AudibleStateToStr(
+    const AudioChannelService::AudibleState& aAudible);
+const char* AudibleChangedReasonToStr(
+    const AudioChannelService::AudibleChangedReasons& aReason);
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/audiochannel/crashtests/1223734.html b/dom/audiochannel/crashtests/1223734.html
new file mode 100644
index 0000000000..1d001eccc4
--- /dev/null
+++ b/dom/audiochannel/crashtests/1223734.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="UTF-8">
+<script>
+
+function boom() {
+    var audio = document.createElement('audio');
+    audio.loop = true;
+    audio.play();
+    document.implementation.createDocument("", "", null).adoptNode(audio);
+}
+
+</script>
+</head>
+<body onload="boom();"></body>
+</html>
diff --git a/dom/audiochannel/crashtests/1339930.html b/dom/audiochannel/crashtests/1339930.html
new file mode 100644
index 0000000000..f817c85975
--- /dev/null
+++ b/dom/audiochannel/crashtests/1339930.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="UTF-8">
+<script>
+window.onload = function(){
+  let x = document.getElementsByTagName("iframe")[0];
+  let w = window.open();
+  let o = window.frames[0];
+  x.remove();
+  o.requestIdleCallback(function(){});
+  w.close();
+};
+</script>
+</head>
+<body>
+<iframe></iframe>
+</body>
+</html>
diff --git a/dom/audiochannel/crashtests/crashtests.list b/dom/audiochannel/crashtests/crashtests.list
new file mode 100644
index 0000000000..3af64ac466
--- /dev/null
+++ b/dom/audiochannel/crashtests/crashtests.list
@@ -0,0 +1,2 @@
+load 1223734.html
+load 1339930.html
diff --git a/dom/audiochannel/moz.build b/dom/audiochannel/moz.build
new file mode 100644
index 0000000000..d006368e7f
--- /dev/null
+++ b/dom/audiochannel/moz.build
@@ -0,0 +1,32 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+with Files("**"):
+    BUG_COMPONENT = ("Core", "Audio/Video: Playback")
+
+XPIDL_SOURCES += [
+    "nsIAudioChannelAgent.idl",
+]
+
+XPIDL_MODULE = "dom_audiochannel"
+
+EXPORTS += [
+    "AudioChannelAgent.h",
+    "AudioChannelService.h",
+]
+
+UNIFIED_SOURCES += [
+    "AudioChannelAgent.cpp",
+    "AudioChannelService.cpp",
+]
+
+LOCAL_INCLUDES += [
+    "/dom/base/",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul"
diff --git a/dom/audiochannel/nsIAudioChannelAgent.idl b/dom/audiochannel/nsIAudioChannelAgent.idl
new file mode 100644
index 0000000000..69a8344449
--- /dev/null
+++ b/dom/audiochannel/nsIAudioChannelAgent.idl
@@ -0,0 +1,121 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface mozIDOMWindow;
+
+typedef uint32_t nsSuspendedTypes;
+
+[scriptable, builtinclass, uuid(2822a840-f009-11e5-a837-0800200c9a66)]
+interface nsISuspendedTypes : nsISupports
+{
+  /**
+   * The suspended enum is used for delaying autoplay video in non-visited tab
+   *
+   * Note: the "remote side" must control the AudioChannelAgent using
+   * nsIAudioChannelAgentCallback.windowSuspendChanged() callback instead using
+   * play/pause methods or any button in the webpage.
+   *
+   * - SUSPENDED_BLOCK
+   * It's used to prevent auto-playing media in inactive page in order to
+   * reduce the power consumption, and the media can't be resumed until the
+   * page becomes active again. It would change the internal state of
+   * MediaElement when it's being blocked/resumed, so it won't trigger the
+   * related JS event. eg. "play" and "pause" event.
+   */
+
+  const uint32_t NONE_SUSPENDED             = 0;
+  const uint32_t SUSPENDED_BLOCK            = 1;
+};
+
+[uuid(15c05894-408e-4798-b527-a8c32d9c5f8c)]
+interface nsIAudioChannelAgentCallback : nsISupports
+{
+  /**
+   * Notified when the window volume/mute is changed
+   */
+  void windowVolumeChanged(in float aVolume, in bool aMuted);
+
+   /**
+   * Notified when the window needs to be suspended or resumed.
+   */
+  void windowSuspendChanged(in uint32_t aSuspend);
+
+  /**
+   * Notified when the capture state is changed.
+   */
+  void windowAudioCaptureChanged(in bool aCapture);
+};
+
+/**
+ * This interface provides an agent for gecko components to participate
+ * in the audio channel service. Gecko components are responsible for
+ *   1. Notifying the agent when they start/stop using this channel.
+ *   2. Notifying the agent when they are audible.
+ *
+ * The agent will invoke a callback to notify Gecko components of
+ *   1. Changes to the playable status of this channel.
+ */
+
+[uuid(4d212770-5d7b-446f-9394-632e351d96ee)]
+interface nsIAudioChannelAgent : nsISupports
+{
+  const long AUDIO_AGENT_STATE_NORMAL               = 0;
+  const long AUDIO_AGENT_STATE_MUTED                = 1;
+  const long AUDIO_AGENT_STATE_FADED                = 2;
+
+  /**
+   * Initialize the agent with a channel type.
+   * Note: This function should only be called once.
+   *
+   * @param window
+   *    The window
+   * @param callback
+   *    1. Once the playable status changes, agent uses this callback function
+   *       to notify Gecko component.
+   *    2. The callback is allowed to be null. Ex: telephony doesn't need to
+   *       listen change of the playable status.
+   *    3. The AudioChannelAgent keeps a strong reference to the callback
+   *       object.
+   */
+  void init(in mozIDOMWindow window, in nsIAudioChannelAgentCallback callback);
+
+  /**
+   * This method is just like init(), except the audio channel agent keeps a
+   * weak reference to the callback object.
+   *
+   * In order for this to work, |callback| must implement
+   * nsISupportsWeakReference.
+   */
+  void initWithWeakCallback(in mozIDOMWindow window,
+                            in nsIAudioChannelAgentCallback callback);
+
+  /**
+   * Notify the agent that we want to start playing.
+   * Note: Gecko component SHOULD call this function first then start to
+   *          play audio stream only when return value is true.
+   */
+  void notifyStartedPlaying(in uint8_t audible);
+
+  /**
+   * Notify the agent we no longer want to play.
+   *
+   * Note : even if notifyStartedPlaying() returned false, the agent would
+   * still be registered with the audio channel service and receive callbacks
+   * for status changes. So notifyStoppedPlaying must still eventually be
+   * called to unregister the agent with the channel service.
+   */
+  void notifyStoppedPlaying();
+
+
+  /**
+   * Notify agent that we already start producing audible data.
+   *
+   * Note : sometime audio might become silent during playing, this method is used to
+   * notify the actually audible state to other services which want to know
+   * about that, ex. tab sound indicator.
+   */
+  void notifyStartedAudible(in uint8_t audible, in uint32_t reason);
+};