Remove mutable from rtc::CriticalSections.

webrtc/voice_engine/dtmf_inband.h

 /*
  *  Copyright (c) 2011 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.
  */
 
@@ skipping 49 matching lines @@
     enum {kDtmfAmpHigh = 32768};
     enum {kDtmfAmpLow  = 23171};        // 3 dB lower than the high frequency
 
     int16_t DtmfFix_generateSignal(int16_t a1_times2,
                                    int16_t a2_times2,
                                    int16_t volume,
                                    int16_t* signal,
                                    int16_t length);
 
 private:
-    mutable rtc::CriticalSection _critSect;
+    rtc::CriticalSection _critSect;
     int32_t _id;
     uint16_t _outputFrequencyHz;  // {8000, 16000, 32000}
     int16_t _oldOutputLow[2];     // Data needed for oscillator model
     int16_t _oldOutputHigh[2];    // Data needed for oscillator model
     int16_t _frameLengthSamples;  // {80, 160, 320}
     int32_t _remainingSamples;
     int16_t _eventCode;           // [0, 15]
     int16_t _attenuationDb;       // [0, 36]
     int32_t _lengthMs;
     bool _reinit;  // 'true' if the oscillator should be reinit for next event
     bool _playing;
     uint32_t _delaySinceLastToneMS; // time since last generated tone [ms]
 };
 
 }  // namespace webrtc
 
 #endif // #ifndef WEBRTC_VOICE_ENGINE_DTMF_INBAND_H_