Introduce ES6 iterator for DOM objects.

Source/bindings/scripts/v8_interface.py

Index: Source/bindings/scripts/v8_interface.py
diff --git a/Source/bindings/scripts/v8_interface.py b/Source/bindings/scripts/v8_interface.py
index 3f807e6489af96915b105f5f0f424c9f08301d32..b4203989f7b672411af124c5f9a09f98a3609aea 100644
--- a/Source/bindings/scripts/v8_interface.py
+++ b/Source/bindings/scripts/v8_interface.py
@@ -101,6 +101,17 @@ def interface_context(interface):
     # [DependentLifetime]
     is_dependent_lifetime = 'DependentLifetime' in extended_attributes
 
+    # [Iterable]
+    iterator_method = None
+    if 'Iterable' in extended_attributes:
+        iterator_operation = IdlOperation(interface.idl_name)
+        iterator_operation.name = 'iterator'
+        iterator_operation.idl_type = IdlType('Iterator')
+        iterator_operation.extended_attributes['RaisesException'] = None
+        iterator_operation.extended_attributes['CallWith'] = 'ScriptState'
+        iterator_method = v8_methods.method_context(interface,
+                                                    iterator_operation)
+
     # [MeasureAs]
     is_measure_as = 'MeasureAs' in extended_attributes
     if is_measure_as:
@@ -164,6 +175,7 @@ def interface_context(interface):
         'is_event_target': inherits_interface(interface.name, 'EventTarget'),
         'is_exception': interface.is_exception,
         'is_node': inherits_interface(interface.name, 'Node'),
+        'iterator_method': iterator_method,
         'measure_as': v8_utilities.measure_as(interface),  # [MeasureAs]
         'parent_interface': parent_interface,
         'pass_cpp_type': cpp_template_type(