Refactor conversion to native.

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 812 matching lines @@
           '        if (!scriptArguments)\n'
           '            goto fail;\n'
           '        RefPtr<ScriptCallStack> scriptCallStack(DartUtilities::createScriptCallStack());\n'
           '        if (!scriptCallStack->size())\n'
           '            return;\n',
           INDEX=len(arguments) + 1)
 
     # Emit arguments.
     start_index = 1 if needs_receiver else 0
     for i, argument in enumerate(arguments):
-      type_info = self._TypeInfo(argument.type.id)
-      self._cpp_impl_includes |= set(type_info.to_native_includes())
       argument_name = DartDomNameOfAttribute(argument)
-      type_info.emit_to_native(
-          body_emitter,
+      argument_expression, type, cls, function = self._TypeInfo(argument.type.id).to_native_info(
           argument,
           (IsOptional(argument) and not self._IsArgumentOptionalInWebCore(node, argument)) or (argument.ext_attrs.get('Optional') == 'DefaultIsNullString'),
           argument_name,
-          'Dart_GetNativeArgument(args, %i)' % (start_index + i))
-      cpp_arguments.append(type_info.argument_expression(argument_name, self._interface.id))
+          self._interface.id)
+
+      body_emitter.Emit(
+          '\n'
+          '        $TYPE $ARGUMENT_NAME = $CLS::$FUNCTION(Dart_GetNativeArgument(args, $INDEX), exception);\n'
+          '        if (exception)\n'
+          '            goto fail;\n',
+          TYPE=type,
+          ARGUMENT_NAME=argument_name,
+          CLS=cls,
+          FUNCTION=function,
+          INDEX=start_index + i)
+      self._cpp_impl_includes.add('"%s.h"' % cls)
+      cpp_arguments.append(argument_expression)
 
     body_emitter.Emit('\n')
 
     if 'NeedsUserGestureCheck' in ext_attrs:
       cpp_arguments.append('DartUtilities::processingUserGesture')
 
     invocation_emitter = body_emitter
     if raises_dom_exception:
       cpp_arguments.append('ec')
       invocation_emitter = body_emitter.Emit(
@@ skipping 96 matching lines @@
     parent_interface = _FindInHierarchy(database, parent_interface, test)
     if parent_interface:
       return parent_interface
 
 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)