Remove webrtc/sound/ subdir.

webrtc/sound/nullsoundsystemfactory.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/nullsoundsystemfactory.h"
-
-#include "webrtc/sound/nullsoundsystem.h"
-
-namespace rtc {
-
-NullSoundSystemFactory::NullSoundSystemFactory() {
-}
-
-NullSoundSystemFactory::~NullSoundSystemFactory() {
-}
-
-bool NullSoundSystemFactory::SetupInstance() {
-  instance_.reset(new NullSoundSystem());
-  return true;
-}
-
-void NullSoundSystemFactory::CleanupInstance() {
-  instance_.reset();
-}
-
-}  // namespace rtc