Add IDLDictionaryBase

third_party/WebKit/Source/bindings/templates/dictionary_impl.h

 {% include 'copyright_block.txt' %}
 #ifndef {{cpp_class}}_h
 #define {{cpp_class}}_h
 
 {% for filename in header_includes %}
 #include "{{filename}}"
 {% endfor %}
 
 namespace blink {
 
 {# FIXME: Add "final" if this class doesn't have subclasses #}
 class {{exported}}{{cpp_class}}{% if parent_cpp_class %} : public {{parent_cpp_class}}{% endif %} {
     DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
 public:
     {{cpp_class}}();
     virtual ~{{cpp_class}}();
 
     {% for member in members %}
     bool {{member.has_method_name}}() const { return {{member.has_method_expression}}; }
     {{member.rvalue_cpp_type}} {{member.cpp_name}}() const { return {{member.getter_expression}}; }
     void {{member.setter_name}}({{member.rvalue_cpp_type}} value) { m_{{member.cpp_name}} = value; }
     {% if member.null_setter_name %}
     void {{member.null_setter_name}}() { m_{{member.cpp_name}} = {{member.member_cpp_type}}(); }
     {% endif %}
 
     {% endfor %}
+    v8::Local<v8::Value> toV8Impl(v8::Local<v8::Object>, v8::Isolate*) const override;
     DECLARE_VIRTUAL_TRACE();
 
 private:
     {% for member in members %}
     {{member.member_cpp_type}} m_{{member.cpp_name}};
     {% endfor %}
 
     friend class V8{{cpp_class}};
 };
 
 } // namespace blink
 
 #endif // {{cpp_class}}_h