Implement tail processing for AudioNodes

third_party/WebKit/Source/platform/audio/DynamicsCompressor.h

 /*
  * Copyright (C) 2011 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
@@ skipping 65 matching lines @@
                unsigned frames_to_process);
   void Reset();
   void SetNumberOfChannels(unsigned);
 
   void SetParameterValue(unsigned parameter_id, float value);
   float ParameterValue(unsigned parameter_id);
 
   float SampleRate() const { return sample_rate_; }
   float Nyquist() const { return sample_rate_ / 2; }
 
-  double TailTime() const { return 0; }
+  double TailTime() const;
   double LatencyTime() const {
     return compressor_.LatencyFrames() / static_cast<double>(SampleRate());
   }
+  bool RequiresTailProcessing() const {
+    // Always return true even if the tail time and latency might both
+    // be zero.
+    return true;
+  }
 
  protected:
   unsigned number_of_channels_;
 
   // m_parameters holds the tweakable compressor parameters.
   float parameters_[kParamLast];
   void InitializeParameters();
 
   float sample_rate_;
 
   // Emphasis filter controls.
   float last_filter_stage_ratio_;
   float last_anchor_;
   float last_filter_stage_gain_;
 
   std::unique_ptr<const float* []> source_channels_;
   std::unique_ptr<float* []> destination_channels_;
 
   // The core compressor.
   DynamicsCompressorKernel compressor_;
 };
 
 }  // namespace blink
 
 #endif  // DynamicsCompressor_h