IDL: Support union type arrays and sequences for method arguments

Source/bindings/templates/union.cpp

Index: Source/bindings/templates/union.cpp
diff --git a/Source/bindings/templates/union.cpp b/Source/bindings/templates/union.cpp
index 9262943d5f18f56e40a48da0df6bb388c4313112..48a358656dc018a3c3efe008af256ac2cb460422 100644
--- a/Source/bindings/templates/union.cpp
+++ b/Source/bindings/templates/union.cpp
@@ -151,5 +151,12 @@ v8::Handle<v8::Value> toV8({{container.cpp_class}}& impl, v8::Handle<v8::Object>
     return v8::Handle<v8::Value>();
 }
 
+{{container.cpp_class}} NativeValueTraits<{{container.cpp_class}}>::nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate, ExceptionState& exceptionState)
+{
+    {{container.cpp_class}} impl;
+    V8{{container.cpp_class}}::toImpl(isolate, value, impl, exceptionState);
+    return impl;
+}
+
 {% endfor %}
 } // namespace blink