IDL: Drop value conversion (V8 -> C++) macros from generated code

Source/bindings/tests/results/core/V8TestInterfaceNode.cpp

Index: Source/bindings/tests/results/core/V8TestInterfaceNode.cpp
diff --git a/Source/bindings/tests/results/core/V8TestInterfaceNode.cpp b/Source/bindings/tests/results/core/V8TestInterfaceNode.cpp
index 7dda941231798ef260bcce413005fc4e9b6ed18e..a388763ffd565c896d79700a50651b69711e61d3 100644
--- a/Source/bindings/tests/results/core/V8TestInterfaceNode.cpp
+++ b/Source/bindings/tests/results/core/V8TestInterfaceNode.cpp
@@ -52,7 +52,9 @@ static void stringAttributeAttributeSetter(v8::Local<v8::Value> v8Value, const v
 {
     v8::Local<v8::Object> holder = info.Holder();
     TestInterfaceNode* impl = V8TestInterfaceNode::toImpl(holder);
-    TOSTRING_VOID(V8StringResource<>, cppValue, v8Value);
+    V8StringResource<> cppValue = v8Value;
+    if (!cppValue.prepare())
+        return;
     impl->setStringAttribute(cppValue);
 }
 
@@ -152,7 +154,9 @@ static void reflectStringAttributeAttributeSetter(v8::Local<v8::Value> v8Value,
 {
     v8::Local<v8::Object> holder = info.Holder();
     Element* impl = V8Element::toImpl(holder);
-    TOSTRING_VOID(V8StringResource<>, cppValue, v8Value);
+    V8StringResource<> cppValue = v8Value;
+    if (!cppValue.prepare())
+        return;
     impl->setAttribute(HTMLNames::reflectstringattributeAttr, cppValue);
 }
 
@@ -182,7 +186,9 @@ static void reflectUrlStringAttributeAttributeSetter(v8::Local<v8::Value> v8Valu
 {
     v8::Local<v8::Object> holder = info.Holder();
     Element* impl = V8Element::toImpl(holder);
-    TOSTRING_VOID(V8StringResource<>, cppValue, v8Value);
+    V8StringResource<> cppValue = v8Value;
+    if (!cppValue.prepare())
+        return;
     impl->setAttribute(HTMLNames::reflecturlstringattributeAttr, cppValue);
 }