Remove mutable from rtc::CriticalSections.

webrtc/voice_engine/level_indicator.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 22 matching lines @@
     void Clear();
 
     // Called on a native capture audio thread (platform dependent) from the
     // AudioTransport::RecordedDataIsAvailable() callback.
     // In Chrome, this method is called on the AudioInputDevice thread.
     void ComputeLevel(const AudioFrame& audioFrame);
 
 private:
     enum { kUpdateFrequency = 10};
 
-    mutable rtc::CriticalSection _critSect;
+    rtc::CriticalSection _critSect;
 
     int16_t _absMax;
     int16_t _count;
     int8_t _currentLevel;
     int16_t _currentLevelFullRange;
 };
 
 }  // namespace voe
 
 }  // namespace webrtc
 
 #endif // WEBRTC_VOICE_ENGINE_LEVEL_INDICATOR_H