Don't clip FFT output values to minDecibels.

third_party/WebKit/Source/platform/audio/AudioUtilities.cpp

 /*
  * 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 19 matching lines @@
 
 namespace AudioUtilities {
 
 float decibelsToLinear(float decibels)
 {
     return powf(10, 0.05f * decibels);
 }
 
 float linearToDecibels(float linear)
 {
-    // It's not possible to calculate decibels for a zero linear value since it would be -Inf.
-    // -1000.0 dB represents a very tiny linear value in case we ever reach this case.
-    ASSERT(linear);
-    if (!linear)
-        return -1000;
+    ASSERT(linear >= 0);
 
     return 20 * log10f(linear);
 }
 
 double discreteTimeConstantForSampleRate(double timeConstant, double sampleRate)
 {
     return 1 - exp(-1 / (sampleRate * timeConstant));
 }
 
 size_t timeToSampleFrame(double time, double sampleRate)
@@ skipping 22 matching lines @@
 
 float maxAudioBufferSampleRate()
 {
     // Windows can support audio sampling rates this high, so allow AudioBuffer rates this high as well.
     return 192000;
 }
 } // namespace AudioUtilities
 
 } // namespace blink