Remove mutable from rtc::CriticalSection members.

webrtc/video/video_send_stream_tests.cc

 /*
  *  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.
  */
 #include <algorithm>  // max
@@ skipping 1062 matching lines @@
       start_bitrate_kbps_ = new_target_bitrate;
       return FakeEncoder::SetRates(new_target_bitrate, framerate);
     }
 
     int GetStartBitrateKbps() const {
       rtc::CritScope lock(&crit_);
       return start_bitrate_kbps_;
     }
 
    private:
-    mutable rtc::CriticalSection crit_;
+    rtc::CriticalSection crit_;
     int start_bitrate_kbps_ GUARDED_BY(crit_);
   };
 
   CreateSenderCall(Call::Config());
 
   test::NullTransport transport;
   CreateSendConfig(1, 0, &transport);
 
   Call::Config::BitrateConfig bitrate_config;
   bitrate_config.start_bitrate_bps =
@@ skipping 1164 matching lines @@
         observation_complete_.Set();
       }
     }
   } test;
 
   RunBaseTest(&test);
 }
 #endif
 
 }  // namespace webrtc