Move smoothing filter to common audio and exp_filter to base/analytics.

webrtc/base/analytics/exp_filter.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.
  */
 
-#ifndef WEBRTC_BASE_EXP_FILTER_H_
-#define WEBRTC_BASE_EXP_FILTER_H_
+#ifndef WEBRTC_BASE_ANALYTICS_EXP_FILTER_H_
+#define WEBRTC_BASE_ANALYTICS_EXP_FILTER_H_
 
 namespace rtc {
 
 // This class can be used, for example, for smoothing the result of bandwidth
 // estimation and packet loss estimation.
 
 class ExpFilter {
  public:
   static const float kValueUndefined;
 
@@ skipping 16 matching lines @@
   // Changes the filter factor base to the given value |alpha|.
   void UpdateBase(float alpha);
 
  private:
   float alpha_;  // Filter factor base.
   float filtered_;  // Current filter output.
   const float max_;
 };
 }  // namespace rtc
 
-#endif  // WEBRTC_BASE_EXP_FILTER_H_
+#endif  // WEBRTC_BASE_ANALYTICS_EXP_FILTER_H_