Remove webrtc/sound/ subdir.

webrtc/sound/platformsoundsystem.cc

-/*
- *  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.
- */
-
-#include "webrtc/sound/platformsoundsystem.h"
-
-#include "webrtc/base/common.h"
-#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
-#include "webrtc/sound/linuxsoundsystem.h"
-#else
-#include "webrtc/sound/nullsoundsystem.h"
-#endif
-
-namespace rtc {
-
-SoundSystemInterface *CreatePlatformSoundSystem() {
-#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
-  return new LinuxSoundSystem();
-#else
-  ASSERT(false && "Not implemented");
-  return new NullSoundSystem();
-#endif
-}
-
-}  // namespace rtc