Make Exception a class, not an interface, and remove the const constructor.

sdk/lib/html/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 os
@@ skipping 791 matching lines @@
       GenerateCall(operation, argument_count, checks)
 
     # TODO: Optimize the dispatch to avoid repeated checks.
     if len(operations) > 1:
       for operation in operations:
         for position, argument in enumerate(operation.arguments):
           if self._IsOptional(operation, argument):
             GenerateChecksAndCall(operation, position)
         GenerateChecksAndCall(operation, len(operation.arguments))
       body.Emit(
-          '    throw const Exception("Incorrect number or type of arguments");'
+          '    throw new ArgumentError("Incorrect number or type of arguments");'
           '\n');
     else:
       operation = operations[0]
       argument_count = len(operation.arguments)
       for position, argument in list(enumerate(operation.arguments))[::-1]:
         if self._IsOptional(operation, argument):
           check = '?%s' % parameter_names[position]
           GenerateCall(operation, position + 1, [check])
           argument_count = position
       GenerateCall(operation, argument_count, [])
@@ skipping 146 matching lines @@
       'svg': DartLibrary('svg', template_loader, library_type, output_dir),
       'html': DartLibrary('html', 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)