Use double for time-related variables

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

Index: third_party/WebKit/Source/modules/webaudio/AudioParamTimeline.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/AudioParamTimeline.cpp b/third_party/WebKit/Source/modules/webaudio/AudioParamTimeline.cpp
index 189aaa81c620a1b06e4c053aea7ee89238244611..182465bd71f14cdad4b01231585a49e0326eef01 100644
--- a/third_party/WebKit/Source/modules/webaudio/AudioParamTimeline.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/AudioParamTimeline.cpp
@@ -730,7 +730,7 @@ float AudioParamTimeline::valuesForFrameRangeImpl(size_t startFrame,
         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
         //