IDL: [NoImplHeader] should not add '#include "None"'

Source/bindings/scripts/v8_types.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 421 matching lines @@
     if native_array_element_type:
         includes_for_type.update(impl_includes_for_type(
                 native_array_element_type, interfaces_info))
         includes_for_type.add('wtf/Vector.h')
 
     base_idl_type = idl_type.base_type
     if idl_type.is_string_type:
         includes_for_type.add('wtf/text/WTFString.h')
     if base_idl_type in interfaces_info:
         interface_info = interfaces_info[idl_type.base_type]
-        includes_for_type.add(interface_info['include_path'])
+        if interface_info['include_path']:
+            includes_for_type.add(interface_info['include_path'])
     if base_idl_type in INCLUDES_FOR_TYPE:
         includes_for_type.update(INCLUDES_FOR_TYPE[base_idl_type])
     if idl_type.is_typed_array:
         return set(['core/dom/DOMTypedArray.h'])
     return includes_for_type
 
 
 def impl_includes_for_type_union(idl_type, interfaces_info):
     includes_for_type = set()
     for member_type in idl_type.member_types:
@@ skipping 491 matching lines @@
     number_of_nullable_member_types_union)
 
 
 def includes_nullable_type_union(idl_type):
     # http://heycam.github.io/webidl/#dfn-includes-a-nullable-type
     return idl_type.number_of_nullable_member_types == 1
 
 IdlTypeBase.includes_nullable_type = False
 IdlNullableType.includes_nullable_type = True
 IdlUnionType.includes_nullable_type = property(includes_nullable_type_union)