Support per-overload [RuntimeEnabled] extended attribute

Source/bindings/scripts/v8_interface.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 # coding=utf-8
 #
 # 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
@@ skipping 735 matching lines @@
             # • a numeric type
             try:
                 method = next(method for idl_type, method in idl_types_methods
                               if idl_type.is_numeric_type)
                 test = '%s->IsNumber()' % cpp_value
                 yield test, method
             except StopIteration:
                 pass
 
     # (Perform automatic type conversion, in order. If any of these match,
-    # that’s the end, and no other tests are needed.)
+    # that’s the end, and no other tests are needed.) To keep this code simple,
+    # we rely on the C++ compiler's dead code elimination to deal with the
+    # redundancy if both cases below trigger.
 
     # 11. Otherwise: if there is an entry in S that has one of the following
     # types at position i of its type list,
     # • DOMString
     # • an enumeration type
     try:
         method = next(method for idl_type, method in idl_types_methods
                       if idl_type.name == 'String' or idl_type.is_enum)
         yield 'true', method
-        return
     except StopIteration:
         pass
 
     # 12. Otherwise: if there is an entry in S that has one of the following
     # types at position i of its type list,
     # • a numeric type
     try:
         method = next(method for idl_type, method in idl_types_methods
                       if idl_type.is_numeric_type)
         yield 'true', method
-        return
     except StopIteration:
         pass
 
 
 ################################################################################
 # Utility functions
 ################################################################################
 
 def Counter(iterable):
     # Once using Python 2.7, using collections.Counter
@@ skipping 302 matching lines @@
         deleter = next(
             method
             for method in interface.operations
             if ('deleter' in method.specials and
                 len(method.arguments) == 1 and
                 str(method.arguments[0].idl_type) == 'DOMString'))
     except StopIteration:
         return None
 
     return property_deleter(deleter)