Verify that correct number of arguments was passed.

tools/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 539 matching lines @@
     if info.callback_args:
       self._AddFutureifiedOperation(info, html_name)
     elif not needs_dispatcher:
       # Bind directly to native implementation
       argument_count = (0 if info.IsStatic() else 1) + len(info.param_infos)
       cpp_callback_name = self._GenerateNativeBinding(
           info.name, argument_count, dart_declaration, 'Callback', is_custom)
       if not is_custom:
         self._GenerateOperationNativeCallback(operation, operation.arguments, cpp_callback_name)
     else:
-      self._GenerateDispatcher(info.operations, dart_declaration, [info.name for info in info.param_infos])
+      self._GenerateDispatcher(info.operations, info.NumberOfRequiredInDart(), dart_declaration, [info.name for info in info.param_infos])
 
-  def _GenerateDispatcher(self, operations, dart_declaration, parameter_names):
+  def _GenerateDispatcher(self, operations, number_of_required_in_dart, dart_declaration, parameter_names):
 
     def GenerateCall(
         stmts_emitter, call_emitter, version, operation, argument_count):
       overload_name = '_%s_%s' % (operation.id, version)
       argument_list = ', '.join(parameter_names[:argument_count])
       call_emitter.Emit('$NAME($ARGS)', NAME=overload_name, ARGS=argument_list)
 
       dart_declaration = '%s%s %s(%s)' % (
           'static ' if operation.is_static else '',
           self.SecureOutputType(operation.type.id),
           overload_name, argument_list)
       cpp_callback_name = self._GenerateNativeBinding(
           overload_name, (0 if operation.is_static else 1) + argument_count,
           dart_declaration, 'Callback', False, False)
       self._GenerateOperationNativeCallback(operation, operation.arguments[:argument_count], cpp_callback_name)
 
     self._GenerateDispatcherBody(
         operations,
         parameter_names,
+        number_of_required_in_dart,
         dart_declaration,
         GenerateCall,
         self._IsArgumentOptionalInWebCore)
 
   def SecondaryContext(self, interface):
     pass
 
   def _GenerateOperationNativeCallback(self, operation, arguments, cpp_callback_name):
     webcore_function_name = operation.ext_attrs.get('ImplementedAs', operation.id)
     function_expression = self._GenerateWebCoreFunctionExpression(webcore_function_name, operation)
@@ skipping 424 matching lines @@
             '    if (Dart_NativeFunction func = $CLASS_NAME::resolver(name, argumentCount))\n'
             '        return func;\n',
             CLASS_NAME=os.path.splitext(os.path.basename(path))[0])
 
 def _IsOptionalStringArgumentInInitEventMethod(interface, operation, argument):
   return (
       interface.id.endswith('Event') and
       operation.id.startswith('init') and
       argument.ext_attrs.get('Default') == 'Undefined' and
       argument.type.id == 'DOMString')