IDL: Merge stringifier/serializer definition from implemented interface

third_party/WebKit/Source/bindings/scripts/idl_definitions.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 369 matching lines @@
         if self.stringifier.attribute:
             self.attributes.append(self.stringifier.attribute)
         elif self.stringifier.operation:
             self.operations.append(self.stringifier.operation)
 
     def merge(self, other):
         """Merge in another interface's members (e.g., partial interface)"""
         self.attributes.extend(other.attributes)
         self.constants.extend(other.constants)
         self.operations.extend(other.operations)
+        if self.serializer is None:
+            self.serializer = other.serializer
+        if self.stringifier is None:
+            self.stringifier = other.stringifier
 
 
 class IdlException(IdlInterface):
     # Properly exceptions and interfaces are distinct, and thus should inherit a
     # common base class (say, "IdlExceptionOrInterface").
     # However, there is only one exception (DOMException), and new exceptions
     # are not expected. Thus it is easier to implement exceptions as a
     # restricted subclass of interfaces.
     # http://www.w3.org/TR/WebIDL/#idl-exceptions
     def __init__(self, idl_name, node):
@@ skipping 707 matching lines @@
         self.visit_typed_object(argument)
 
     def visit_iterable(self, iterable):
         self.visit_typed_object(iterable)
 
     def visit_maplike(self, maplike):
         self.visit_typed_object(maplike)
 
     def visit_setlike(self, setlike):
         self.visit_typed_object(setlike)