diff -r 000000000000 -r 6474c204b198 dom/system/gonk/AudioChannelManager.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/system/gonk/AudioChannelManager.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,156 @@
+/* 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 "nsIDOMClassInfo.h"
+#include "nsIDOMEvent.h"
+#include "nsIDOMEventListener.h"
+#include "nsPIDOMWindow.h"
+#include "nsIDocShell.h"
+#include "nsIPermissionManager.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "AudioChannelManager.h"
+#include "mozilla/dom/AudioChannelManagerBinding.h"
+
+using namespace mozilla::hal;
+
+namespace mozilla {
+namespace dom {
+namespace system {
+
+NS_IMPL_QUERY_INTERFACE_INHERITED(AudioChannelManager, DOMEventTargetHelper,
+                                  nsIDOMEventListener)
+NS_IMPL_ADDREF_INHERITED(AudioChannelManager, DOMEventTargetHelper)
+NS_IMPL_RELEASE_INHERITED(AudioChannelManager, DOMEventTargetHelper)
+
+AudioChannelManager::AudioChannelManager()
+  : mState(SWITCH_STATE_UNKNOWN)
+  , mVolumeChannel(-1)
+{
+  RegisterSwitchObserver(SWITCH_HEADPHONES, this);
+  mState = GetCurrentSwitchState(SWITCH_HEADPHONES);
+  SetIsDOMBinding();
+}
+
+AudioChannelManager::~AudioChannelManager()
+{
+  UnregisterSwitchObserver(SWITCH_HEADPHONES, this);
+
+  nsCOMPtr<EventTarget> target = do_QueryInterface(GetOwner());
+  NS_ENSURE_TRUE_VOID(target);
+
+  target->RemoveSystemEventListener(NS_LITERAL_STRING("visibilitychange"),
+                                    this,
+                                    /* useCapture = */ true);
+}
+
+void
+AudioChannelManager::Init(nsPIDOMWindow* aWindow)
+{
+  BindToOwner(aWindow->IsOuterWindow() ?
+              aWindow->GetCurrentInnerWindow() : aWindow);
+
+  nsCOMPtr<nsIDOMEventTarget> target = do_QueryInterface(GetOwner());
+  NS_ENSURE_TRUE_VOID(target);
+
+  target->AddSystemEventListener(NS_LITERAL_STRING("visibilitychange"),
+                                 this,
+                                 /* useCapture = */ true,
+                                 /* wantsUntrusted = */ false);
+}
+
+JSObject*
+AudioChannelManager::WrapObject(JSContext* aCx)
+{
+  return AudioChannelManagerBinding::Wrap(aCx, this);
+}
+
+void
+AudioChannelManager::Notify(const SwitchEvent& aEvent)
+{
+  mState = aEvent.status();
+
+  DispatchTrustedEvent(NS_LITERAL_STRING("headphoneschange"));
+}
+
+bool
+AudioChannelManager::SetVolumeControlChannel(const nsAString& aChannel)
+{
+  if (aChannel.EqualsASCII("publicnotification")) {
+    return false;
+  }
+
+  AudioChannel newChannel = AudioChannelService::GetAudioChannel(aChannel);
+
+  // Only normal channel doesn't need permission.
+  if (newChannel != AudioChannel::Normal) {
+    nsCOMPtr<nsIPermissionManager> permissionManager =
+      do_GetService(NS_PERMISSIONMANAGER_CONTRACTID);
+    if (!permissionManager) {
+      return false;
+    }
+    uint32_t perm = nsIPermissionManager::UNKNOWN_ACTION;
+    permissionManager->TestPermissionFromWindow(GetOwner(),
+      nsCString(NS_LITERAL_CSTRING("audio-channel-") +
+      NS_ConvertUTF16toUTF8(aChannel)).get(), &perm);
+    if (perm != nsIPermissionManager::ALLOW_ACTION) {
+      return false;
+    }
+  }
+
+  if (mVolumeChannel == (int32_t)newChannel) {
+    return true;
+  }
+
+  mVolumeChannel = (int32_t)newChannel;
+
+  NotifyVolumeControlChannelChanged();
+  return true;
+}
+
+bool
+AudioChannelManager::GetVolumeControlChannel(nsAString & aChannel)
+{
+  if (mVolumeChannel >= 0) {
+    AudioChannelService::GetAudioChannelString(
+                                      static_cast<AudioChannel>(mVolumeChannel),
+                                      aChannel);
+  } else {
+    aChannel.AssignASCII("");
+  }
+
+  return true;
+}
+
+void
+AudioChannelManager::NotifyVolumeControlChannelChanged()
+{
+  nsCOMPtr<nsIDocShell> docshell = do_GetInterface(GetOwner());
+  NS_ENSURE_TRUE_VOID(docshell);
+
+  bool isActive = false;
+  docshell->GetIsActive(&isActive);
+
+  AudioChannelService* service = AudioChannelService::GetAudioChannelService();
+  if (isActive) {
+    service->SetDefaultVolumeControlChannel(mVolumeChannel, isActive);
+  } else {
+    service->SetDefaultVolumeControlChannel(-1, isActive);
+  }
+}
+
+NS_IMETHODIMP
+AudioChannelManager::HandleEvent(nsIDOMEvent* aEvent)
+{
+  nsAutoString type;
+  aEvent->GetType(type);
+
+  if (type.EqualsLiteral("visibilitychange")) {
+    NotifyVolumeControlChannelChanged();
+  }
+  return NS_OK;
+}
+
+} // namespace system
+} // namespace dom
+} // namespace mozilla