Change the default panning mode from HRTF to equal-power

Source/modules/webaudio/PannerNode.idl

Index: Source/modules/webaudio/PannerNode.idl
diff --git a/Source/modules/webaudio/PannerNode.idl b/Source/modules/webaudio/PannerNode.idl
index cbd1fc8f797315f018634e38858fb9cfe55079a8..c9785c3b9b7ca3ab390747bb0163f2b8b97cbb05 100644
--- a/Source/modules/webaudio/PannerNode.idl
+++ b/Source/modules/webaudio/PannerNode.idl
@@ -37,7 +37,7 @@ enum DistanceModelType {
     NoInterfaceObject,
     Conditional=WEB_AUDIO
 ] interface PannerNode : AudioNode {
-    // Default model for stereo is HRTF
+    // Default model for stereo is equalpower.
     attribute PanningModelType panningModel;
 
     // Uses a 3D cartesian coordinate system
@@ -56,4 +56,4 @@ enum DistanceModelType {
     attribute double coneInnerAngle;
     attribute double coneOuterAngle;
     attribute double coneOuterGain;
-};
+};