diff -r 000000000000 -r 6474c204b198 dom/system/gonk/AudioChannelManager.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/system/gonk/AudioChannelManager.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,76 @@
+/* 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_system_AudioChannelManager_h
+#define mozilla_dom_system_AudioChannelManager_h
+
+#include "mozilla/DOMEventTargetHelper.h"
+#include "mozilla/Hal.h"
+#include "mozilla/HalTypes.h"
+#include "AudioChannelService.h"
+
+namespace mozilla {
+namespace hal {
+class SwitchEvent;
+typedef Observer<SwitchEvent> SwitchObserver;
+} // namespace hal
+
+namespace dom {
+namespace system {
+
+class AudioChannelManager MOZ_FINAL
+  : public DOMEventTargetHelper
+  , public hal::SwitchObserver
+  , public nsIDOMEventListener
+{
+public:
+  AudioChannelManager();
+  virtual ~AudioChannelManager();
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIDOMEVENTLISTENER
+
+  void Notify(const hal::SwitchEvent& aEvent);
+
+  void Init(nsPIDOMWindow* aWindow);
+
+  /**
+   * WebIDL Interface
+   */
+
+  nsPIDOMWindow* GetParentObject() const
+  {
+     return GetOwner();
+  }
+
+  virtual JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE;
+
+  bool Headphones() const
+  {
+    // Bug 929139 - Remove the assert check for SWITCH_STATE_UNKNOWN.
+    // If any devices (ex: emulator) didn't have the corresponding sys node for
+    // headset switch state then GonkSwitch will report the unknown state.
+    // So it is possible to get unknown state here.
+    return mState != hal::SWITCH_STATE_OFF &&
+           mState != hal::SWITCH_STATE_UNKNOWN;
+  }
+
+  bool SetVolumeControlChannel(const nsAString& aChannel);
+
+  bool GetVolumeControlChannel(nsAString& aChannel);
+
+  IMPL_EVENT_HANDLER(headphoneschange)
+
+private:
+  void NotifyVolumeControlChannelChanged();
+
+  hal::SwitchState mState;
+  int32_t mVolumeChannel;
+};
+
+} // namespace system
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_system_AudioChannelManager_h