Add support for switching the audio output device for HTMLMediaElements.

media/audio/audio_output_ipc.h

Index: media/audio/audio_output_ipc.h
diff --git a/media/audio/audio_output_ipc.h b/media/audio/audio_output_ipc.h
index f85d8e0195325dfc3add33238bc77d56a9d85cc2..d59aba4debc5700301759dc776d2bbbab2214333 100644
--- a/media/audio/audio_output_ipc.h
+++ b/media/audio/audio_output_ipc.h
@@ -5,10 +5,14 @@
 #ifndef MEDIA_AUDIO_AUDIO_OUTPUT_IPC_H_
 #define MEDIA_AUDIO_AUDIO_OUTPUT_IPC_H_
 
+#include <string>
+
+#include "base/callback.h"
 #include "base/memory/shared_memory.h"
 #include "base/sync_socket.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/media_export.h"
+#include "url/gurl.h"
 
 namespace media {
 
@@ -27,6 +31,16 @@ class MEDIA_EXPORT AudioOutputIPCDelegate {
     kStateLast = kError
   };
 
+  // Result of an audio output device switch operation
+  enum DeviceSwitchResult {
+    kSuccess = 0,
+    kNotFound,
+    kSecurityError,
+    kOtherError,
+    kDeviceSwitchResultLast = kOtherError
+  };
+
+
   // Called when state of an audio stream has changed.
   virtual void OnStateChanged(State state) = 0;
 
@@ -42,6 +56,9 @@ class MEDIA_EXPORT AudioOutputIPCDelegate {
                                base::SyncSocket::Handle socket_handle,
                                int length) = 0;
 
+  // Called when an attempt to switch the output device has been completed
+  virtual void OnDeviceSwitched(int request_id, DeviceSwitchResult result) = 0;
+
   // Called when the AudioOutputIPC object is going away and/or when the IPC
   // channel has been closed and no more ipc requests can be made.
   // Implementations should delete their owned AudioOutputIPC instance
@@ -84,6 +101,13 @@ class MEDIA_EXPORT AudioOutputIPC {
 
   // Sets the volume of the audio stream.
   virtual void SetVolume(double volume) = 0;
+
+  // Switches the output device of the audio stream. This should generate a
+  // call to AudioOutputController::SwitchOutputDevice().
+  virtual void SwitchDevice(const std::string& device_id,
+                            const GURL& security_origin,
+                            int request_id,
+                            const base::Callback<void(int)>& callback) = 0;
 };
 
 }  // namespace media