Verify that correct number of arguments was passed.

tools/dom/scripts/systemhtml.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 system to generate
 Dart:html APIs from the IDL database."""
 
 import emitter
 import monitored
@@ skipping 993 matching lines @@
 
     declaration = '%s%s%s %s(%s)' % (
         self._Metadata(info.type_name, info.declared_name),
         'static ' if info.IsStatic() else '',
         return_type,
         html_name,
         info.ParametersDeclaration(InputType))
     self._GenerateDispatcherBody(
         operations,
         parameter_names,
+        info.NumberOfRequiredInDart(),
         declaration,
         GenerateCall,
         lambda _, argument: IsOptional(argument),
         can_omit_type_check=lambda type, pos: type == parameter_types[pos])
 
   def _AddInterfaceOperation(self, info, html_name):
     self._members_emitter.Emit(
         '\n'
         '  $TYPE $NAME($PARAMS);\n',
         TYPE=self.SecureOutputType(info.type_name),
@@ skipping 150 matching lines @@
     for library_name in libraries:
       self._libraries[library_name] = DartLibrary(
           library_name, template_loader, library_type, output_dir)
 
   def AddFile(self, basename, library_name, path):
     self._libraries[library_name].AddFile(path)
 
   def Emit(self, emitter, auxiliary_dir):
     for lib in self._libraries.values():
       lib.Emit(emitter, auxiliary_dir)