Remove type of panningModelType "soundfield".

Source/bindings/v8/custom/V8PannerNodeCustom.cpp

Index: Source/bindings/v8/custom/V8PannerNodeCustom.cpp
diff --git a/Source/bindings/v8/custom/V8PannerNodeCustom.cpp b/Source/bindings/v8/custom/V8PannerNodeCustom.cpp
index e6a14afac5308f9beaaaa5e562f8a20a3a64dfbc..f4d32e1a690f41c55f11057aa417e64f2437bb57 100644
--- a/Source/bindings/v8/custom/V8PannerNodeCustom.cpp
+++ b/Source/bindings/v8/custom/V8PannerNodeCustom.cpp
@@ -50,7 +50,7 @@ void V8PannerNode::panningModelAttributeSetterCustom(v8::Local<v8::Value> value,
 
     if (value->IsString()) {
         String model = toCoreString(value.As<v8::String>());
-        if (model == "equalpower" || model == "HRTF" || model == "soundfield") {
+        if (model == "equalpower" || model == "HRTF") {
             imp->setPanningModel(model);
             return;
         }