Remove all calls to node::MakeCallback

node::MakeCallback is doing too much for us, avoid calling it.

atom/common/native_mate_converters/string16_converter.h

@@ -29,6 +29,12 @@ struct Converter<base::string16> {
   }
 };
 
+inline v8::Local<v8::String> StringToV8(
+    v8::Isolate* isolate,
+    const base::string16& input) {
+  return ConvertToV8(isolate, input).As<v8::String>();
+}
+
 }  // namespace mate
 
 #endif  // ATOM_COMMON_NATIVE_MATE_CONVERTERS_STRING16_CONVERTER_H_