Add support for the audio-output-device switching IPC mechanism to the renderer lower layers (media…

media/audio/null_audio_sink.cc

Index: media/audio/null_audio_sink.cc
diff --git a/media/audio/null_audio_sink.cc b/media/audio/null_audio_sink.cc
index e737c437c9c8d47a2af1ae90a805cfa1f49bb4ba..fc5e900d7059c053ea5507d64fb8b13774a767d5 100644
--- a/media/audio/null_audio_sink.cc
+++ b/media/audio/null_audio_sink.cc
@@ -5,6 +5,7 @@
 #include "media/audio/null_audio_sink.h"
 
 #include "base/bind.h"
+#include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "media/audio/fake_audio_worker.h"
 #include "media/base/audio_hash.h"
@@ -70,6 +71,13 @@ bool NullAudioSink::SetVolume(double volume) {
   return volume == 0.0;
 }
 
+void NullAudioSink::SwitchOutputDevice(const std::string& device_id,
+                                       const GURL& security_origin,
+                                       const SwitchOutputDeviceCB& callback) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  callback.Run(SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_SUPPORTED);
+}
+
 void NullAudioSink::CallRender() {
   DCHECK(task_runner_->BelongsToCurrentThread());