Properly generate MutationCallback in dart:html.

lib/dom/scripts/systemnative.py

 #!/usr/bin/python
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 """This module provides shared functionality for the systems to generate
 native binding from the IDL database."""
 
 import emitter
 import os
@@ skipping 25 matching lines @@
     for operation in interface.operations:
       if operation.type.id == 'void':
         return_prefix = ''
         error_return = ''
       else:
         return_prefix = 'return '
         error_return = ' false'
 
       parameters = []
       arguments = []
+      conversion_includes = []
       for argument in operation.arguments:
         argument_type_info = self._type_registry.TypeInfo(argument.type.id)
         parameters.append('%s %s' % (argument_type_info.parameter_type(),
                                      argument.id))
         arguments.append(argument_type_info.to_dart_conversion(argument.id))
-        cpp_impl_includes |= set(argument_type_info.conversion_includes())
+        conversion_includes.extend(argument_type_info.conversion_includes())
 
       native_return_type = self._type_registry.TypeInfo(operation.type.id).native_type()
       cpp_header_handlers_emitter.Emit(
           '\n'
           '    virtual $TYPE handleEvent($PARAMETERS);\n',
           TYPE=native_return_type, PARAMETERS=', '.join(parameters))
 
+      if 'Custom' in operation.ext_attrs:
+        continue
+
+      cpp_impl_includes |= set(conversion_includes)
       arguments_declaration = 'Dart_Handle arguments[] = { %s }' % ', '.join(arguments)
       if not len(arguments):
         arguments_declaration = 'Dart_Handle* arguments = 0'
       cpp_impl_handlers_emitter.Emit(
           '\n'
           '$TYPE $CLASS_NAME::handleEvent($PARAMETERS)\n'
           '{\n'
           '    if (!m_callback.isolate()->isAlive())\n'
           '        return$ERROR_RETURN;\n'
           '    DartIsolate::Scope scope(m_callback.isolate());\n'
@@ skipping 875 matching lines @@
 
 def _IsArgumentOptionalInWebCore(argument):
   return IsOptional(argument) and not 'Callback' in argument.ext_attrs
 
 def _ToWebKitName(name):
   name = name[0].lower() + name[1:]
   name = re.sub(r'^(hTML|uRL|jS|xML|xSLT)', lambda s: s.group(1).lower(),
                 name)
   return re.sub(r'^(create|exclusive)', lambda s: 'is' + s.group(1).capitalize(),
                 name)