Revert of Compute tail time from Biquad coefficients

third_party/WebKit/Source/modules/webaudio/BiquadDSPKernel.h

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 57 matching lines @@
   // dezippering is used to slowly change the parameters.
   void UpdateCoefficientsIfNecessary(int);
   // Update the biquad cofficients with the given parameters
   void UpdateCoefficients(int,
                           const float* frequency,
                           const float* q,
                           const float* gain,
                           const float* detune);
 
  private:
-  // Compute the tail time using the BiquadFilter coefficients at
-  // index |coef_index|.
-  void UpdateTailTime(int coef_index);
-
   // Synchronize process() with getting and setting the filter coefficients.
   mutable Mutex process_lock_;
-
-  // The current tail time for biquad filter.
-  double tail_time_;
 };
 
 }  // namespace blink
 
 #endif  // BiquadDSPKernel_h