Split Dictionary's get and convert into DictionaryHelper.

Source/bindings/templates/interface.cpp

Index: Source/bindings/templates/interface.cpp
diff --git a/Source/bindings/templates/interface.cpp b/Source/bindings/templates/interface.cpp
index 8e4c58aa543194294241d3a4babc939e3c57ded9..0a6e1b2260f752f33805eb957aa9b3dd9a78cf0c 100644
--- a/Source/bindings/templates/interface.cpp
+++ b/Source/bindings/templates/interface.cpp
@@ -805,14 +805,14 @@ bool initialize{{cpp_class}}({{cpp_class}}Init& eventInit, const Dictionary& opt
                not attribute.idl_type == 'any')%}
     {% set is_nullable = 'true' if attribute.is_nullable else 'false' %}
     {% if attribute.deprecate_as %}
-    if (options.convert(conversionContext.setConversionType("{{attribute.idl_type}}", {{is_nullable}}), "{{attribute.name}}", eventInit.{{attribute.cpp_name}})) {
+    if (DictionaryHelper::convert(options, conversionContext.setConversionType("{{attribute.idl_type}}", {{is_nullable}}), "{{attribute.name}}", eventInit.{{attribute.cpp_name}})) {
         if (options.hasProperty("{{attribute.name}}"))
             UseCounter::countDeprecation(callingExecutionContext(info.GetIsolate()), UseCounter::{{attribute.deprecate_as}});
     } else {
         return false;
     }
     {% else %}
-    if (!options.convert(conversionContext.setConversionType("{{attribute.idl_type}}", {{is_nullable}}), "{{attribute.name}}", eventInit.{{attribute.cpp_name}}))
+    if (!DictionaryHelper::convert(options, conversionContext.setConversionType("{{attribute.idl_type}}", {{is_nullable}}), "{{attribute.name}}", eventInit.{{attribute.cpp_name}}))
         return false;
     {% endif %}
     {% endfor %}