Revert of Add support for the audio-output-device switching IPC mechanism to the renderer lower...

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 fc5e900d7059c053ea5507d64fb8b13774a767d5..e737c437c9c8d47a2af1ae90a805cfa1f49bb4ba 100644
--- a/media/audio/null_audio_sink.cc
+++ b/media/audio/null_audio_sink.cc
@@ -5,7 +5,6 @@
 #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"
@@ -71,13 +70,6 @@
   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());