Revert of Compute tail time from Biquad coefficients

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

Index: third_party/WebKit/Source/modules/webaudio/BiquadDSPKernel.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/BiquadDSPKernel.cpp b/third_party/WebKit/Source/modules/webaudio/BiquadDSPKernel.cpp
index e45539e60f03b6d33cdcb838976eb8a5658f2f6a..e5384a5606c81133918d0a94324a91ec930483aa 100644
--- a/third_party/WebKit/Source/modules/webaudio/BiquadDSPKernel.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/BiquadDSPKernel.cpp
@@ -31,6 +31,13 @@
 
 namespace blink {
 
+// FIXME: As a recursive linear filter, depending on its parameters, a biquad
+// filter can have an infinite tailTime. In practice, Biquad filters do not
+// usually (except for very high resonance values) have a tailTime of longer
+// than approx. 200ms. This value could possibly be calculated based on the
+// settings of the Biquad.
+static const double kMaxBiquadDelayTime = 0.2;
+
 void BiquadDSPKernel::UpdateCoefficientsIfNecessary(int frames_to_process) {
   if (GetBiquadProcessor()->FilterCoefficientsDirty()) {
     float cutoff_frequency[AudioUtilities::kRenderQuantumFrames];
@@ -114,23 +121,6 @@
         break;
     }
   }
-
-  UpdateTailTime(number_of_frames - 1);
-}
-
-void BiquadDSPKernel::UpdateTailTime(int coef_index) {
-  // A reasonable upper limit for the tail time.  While it's easy to
-  // create biquad filters whose tail time can be much larger than
-  // this, limit the maximum to this value so that we don't keep such
-  // nodes alive "forever".
-  // TODO: What is a reasonable upper limit?
-  const double kMaxTailTime = 30;
-
-  double sample_rate = SampleRate();
-  double tail =
-      biquad_.TailFrame(coef_index, kMaxTailTime * sample_rate) / sample_rate;
-
-  tail_time_ = clampTo(tail, 0.0, kMaxTailTime);
 }
 
 void BiquadDSPKernel::Process(const float* source,
@@ -209,7 +199,7 @@
 }
 
 double BiquadDSPKernel::TailTime() const {
-  return tail_time_;
+  return kMaxBiquadDelayTime;
 }
 
 double BiquadDSPKernel::LatencyTime() const {