NetEq: Convert AverageIAT from int to float calculations

webrtc/modules/audio_coding/neteq/delay_manager.h

 /*
  *  Copyright (c) 2012 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 54 matching lines @@
 
   // Resets the DelayManager and the associated DelayPeakDetector.
   virtual void Reset();
 
   // Calculates the average inter-arrival time deviation from the histogram.
   // The result is returned as parts-per-million deviation from the nominal
   // inter-arrival time. That is, if the average inter-arrival time is equal to
   // the nominal frame time, the return value is zero. A positive value
   // corresponds to packet spacing being too large, while a negative value means
   // that the packets arrive with less spacing than expected.
-  virtual int AverageIAT() const;
+  virtual double EstimatedClockDriftPpm() const;
 
   // Returns true if peak-mode is active. That is, delay peaks were observed
   // recently. This method simply asks for the same information from the
   // DelayPeakDetector object.
   virtual bool PeakFound() const;
 
   // Reset the inter-arrival time counter to 0.
   virtual void ResetPacketIatCount();
 
   // Writes the lower and higher limits which the buffer level should stay
@@ skipping 74 matching lines @@
   // Time elapsed since maximum was observed.
   std::unique_ptr<TickTimer::Stopwatch> max_iat_stopwatch_;
   DelayPeakDetector& peak_detector_;
   int last_pack_cng_or_dtmf_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(DelayManager);
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_DELAY_MANAGER_H_