[bindings] Implement an ExperimentEnabled IDL extended attribute.

third_party/WebKit/Source/bindings/scripts/v8_utilities.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 347 matching lines @@
     return interfaces_info.get(name, {}).get('implemented_as') or name
 
 
 def cpp_name_or_partial(interface):
     cpp_class_name = cpp_name(interface)
     if interface.is_partial:
         return ''.join([cpp_class_name, 'Partial'])
     return cpp_class_name
 
 
+def is_experimental_api(interface):
+    return 'ExperimentEnabled' in interface.extended_attributes
+
+
+def experimental_api_name(interface):
+    return interface.extended_attributes['ExperimentEnabled'] if is_experimental_api(interface) else None
+
+
 # [MeasureAs]
 def measure_as(definition_or_member, interface):
     extended_attributes = definition_or_member.extended_attributes
     if 'MeasureAs' in extended_attributes:
         includes.add('core/frame/UseCounter.h')
         return lambda suffix: extended_attributes['MeasureAs']
     if 'Measure' in extended_attributes:
         includes.add('core/frame/UseCounter.h')
         measure_as_name = capitalize(definition_or_member.name)
         if interface is not None:
@@ skipping 200 matching lines @@
     except StopIteration:
         return None
 
 
 IdlInterface.indexed_property_getter = property(indexed_property_getter)
 IdlInterface.indexed_property_setter = property(indexed_property_setter)
 IdlInterface.indexed_property_deleter = property(indexed_property_deleter)
 IdlInterface.named_property_getter = property(named_property_getter)
 IdlInterface.named_property_setter = property(named_property_setter)
 IdlInterface.named_property_deleter = property(named_property_deleter)