Remove webrtc/sound/ subdir.

webrtc/sound/platformsoundsystem.h

Index: webrtc/sound/platformsoundsystem.h
diff --git a/webrtc/sound/platformsoundsystem.h b/webrtc/sound/platformsoundsystem.h
deleted file mode 100644
index 40eff264d8326ecb25e5b4c6f620e5a9bb68f2fb..0000000000000000000000000000000000000000
--- a/webrtc/sound/platformsoundsystem.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#ifndef WEBRTC_SOUND_PLATFORMSOUNDSYSTEM_H_
-#define WEBRTC_SOUND_PLATFORMSOUNDSYSTEM_H_
-
-namespace rtc {
-
-class SoundSystemInterface;
-
-// Creates the sound system implementation for this platform.
-SoundSystemInterface *CreatePlatformSoundSystem();
-
-}  // namespace rtc
-
-#endif  // WEBRTC_SOUND_PLATFORMSOUNDSYSTEM_H_