Make interface definitions accept both 'interface' and 'exception' as a keyword.

lib/dom/scripts/idlparser.py

 #!/usr/bin/python
 # Copyright (c) 2011, 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.
 
 import re
 import subprocess
 import tempfile
 
 from pegparser import *
@@ skipping 72 matching lines @@
         # FremontCut:
         [MAYBE(_Annotations), MAYBE(ExtAttrs), 'module', Id,
          '{', _Definitions, '}', MAYBE(';')])
 
     def Interface():
       return syntax_switch(
         # Web IDL:
         [MAYBE(ExtAttrs), 'interface', Id, MAYBE(_ParentInterfaces),
          MAYBE(['{', MAYBE(MANY(_Member)), '}']), ';'],
         # WebKit:
-        ['interface', MAYBE(ExtAttrs), Id, MAYBE(_ParentInterfaces),
+        [OR('interface', 'exception'), MAYBE(ExtAttrs), Id, MAYBE(_ParentInterfaces),
          MAYBE(['{', MAYBE(MANY(_Member)), '}']), MAYBE(';')],
         # FremontCut:
         [MAYBE(_Annotations), MAYBE(ExtAttrs), 'interface',
          Id, MAYBE(_ParentInterfaces), MAYBE(['{', MAYBE(MANY(_Member)),
          '}']), ';'])
 
     def _Member():
       return syntax_switch(
         # Web IDL:
         OR(Const, Attribute, Operation, ExtAttrs),
@@ skipping 329 matching lines @@
     Args:
       content -- text to parse.
       defines -- an array of pre-processor defines.
       includePaths -- an array of path strings used by the
         gcc pre-processor.
     """
     if self._syntax == WEBKIT_SYNTAX:
       content = self._pre_process(content, defines, includePaths)
 
     return self._pegparser.parse(content)