Introduce ES6 iterator for DOM objects.

Source/bindings/templates/interface_base.cpp

Index: Source/bindings/templates/interface_base.cpp
diff --git a/Source/bindings/templates/interface_base.cpp b/Source/bindings/templates/interface_base.cpp
index 68a7cc5d3b873c49082a76d81c027af21e7a3e38..6d68242671238fb63b08200e6a7537ec2fd25bbc 100644
--- a/Source/bindings/templates/interface_base.cpp
+++ b/Source/bindings/templates/interface_base.cpp
@@ -109,6 +109,14 @@ template <typename T> void V8_USE(T) { }
 {% endfor %}
 {% endif %}
 {% endfor %}
+{% if is_iterable %}
+namespace symbol {
+{% for world_suffix in iterator_method.world_suffixes %}
+{{generate_method(iterator_method, world_suffix)}}
+{{method_callback(iterator_method, world_suffix, '::symbol')}}
+{% endfor %}
+} // namespace symbol
+{% endif %}
 {% block origin_safe_method_setter %}{% endblock %}
 {# Constructors #}
 {% for constructor in constructors %}