Use double for time-related variables

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

 /*
  * 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 712 matching lines @@
     } else if (nextEventType == ParamEvent::ExponentialRampToValue) {
       if (value1 * value2 <= 0) {
         // It's an error if value1 and value2 have opposite signs or if one of
         // them is zero.  Handle this by propagating the previous value, and
         // making it the default.
         value = value1;
 
         for (; writeIndex < fillToFrame; ++writeIndex)
           values[writeIndex] = value;
       } else {
-        float numSampleFrames = deltaTime * sampleRate;
+        double numSampleFrames = deltaTime * sampleRate;
         // The value goes exponentially from value1 to value2 in a duration of
         // deltaTime seconds according to
         //
         //  v(t) = v1*(v2/v1)^((t-t1)/(t2-t1))
         //
         // Let c be currentFrame and F be the sampleRate.  Then we want to
         // sample v(t) at times t = (c + k)/F for k = 0, 1, ...:
         //
         //   v((c+k)/F) = v1*(v2/v1)^(((c/F+k/F)-t1)/(t2-t1))
         //              = v1*(v2/v1)^((c/F-t1)/(t2-t1))
@@ skipping 352 matching lines @@
   // propagate the last value to the end of the values buffer.
   for (; writeIndex < numberOfValues; ++writeIndex)
     values[writeIndex] = value;
 
   // This value is used to set the .value attribute of the AudioParam.  it
   // should be the last computed value.
   return values[numberOfValues - 1];
 }
 
 }  // namespace blink