Enable cpplint and fix cpplint errors in webrtc/*audio

webrtc/common_audio/include/audio_util.h

 /*
  *  Copyright (c) 2013 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_COMMON_AUDIO_INCLUDE_AUDIO_UTIL_H_
 #define WEBRTC_COMMON_AUDIO_INCLUDE_AUDIO_UTIL_H_
 
+#include <algorithm>
 #include <limits>
 #include <cstring>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 typedef std::numeric_limits<int16_t> limits_int16;
 
@@ skipping 154 matching lines @@
 
 template <>
 void DownmixInterleavedToMono<int16_t>(const int16_t* interleaved,
                                        size_t num_frames,
                                        int num_channels,
                                        int16_t* deinterleaved);
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_AUDIO_INCLUDE_AUDIO_UTIL_H_