IDL: Merge duplicating local variable assignment in attribute_getter

Source/bindings/scripts/v8_attributes.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 155 matching lines @@
     # avoid the overhead of using a Ref<> temporary, but for some cases
     # (nullable types, EventHandler, [CachedAttribute], or if there are
     # exceptions), we need to use a local variable.
     # FIXME: check if compilers are smart enough to inline this, and if so,
     # always use a local variable (for readability and CG simplicity).
     release = False
     if (idl_type.is_nullable or
         base_idl_type == 'EventHandler' or
         'CachedAttribute' in extended_attributes or
         'ReflectOnly' in extended_attributes or
+        context['is_keep_alive_for_gc'] or
         context['is_getter_raises_exception']):
         context['cpp_value_original'] = cpp_value
         cpp_value = 'v8Value'
         # EventHandler has special handling
         if base_idl_type != 'EventHandler' and idl_type.is_interface_type:
             release = True
 
     def v8_set_return_value_statement(for_main_world=False):
         if context['is_keep_alive_for_gc']:
             return 'v8SetReturnValue(info, wrapper)'
@@ skipping 245 matching lines @@
     lambda self: strip_suffix(self.base_type, 'Constructor'))
 
 
 def is_constructor_attribute(attribute):
     # FIXME: replace this with [ConstructorAttribute] extended attribute
     return attribute.idl_type.base_type.endswith('Constructor')
 
 
 def constructor_getter_context(interface, attribute, context):
     context['needs_constructor_getter_callback'] = context['measure_as'] or context['deprecate_as']