Migrate to new indexed getter marking scheme.

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 690 matching lines @@
     # In the non-root case we have to choose between:
     #
     #   class YImpl extends XImpl { add List<T> methods; }
     #
     # and
     #
     #   class YImpl extends ListBase<T> { copies of transitive XImpl methods; }
     #
 
     ext_attrs = self._interface.ext_attrs
-    has_indexed_getter = ('IndexedGetter' in ext_attrs or
-      'CustomIndexedSetter' in ext_attrs)
+    has_indexed_getter = 'CustomIndexedGetter' in ext_attrs
+    for operation in self._interface.operations:
+      if operation.id == 'item' and 'getter' in operation.specials:
+        has_indexed_getter = True
+        break
 
     if has_indexed_getter:
       indexed_getter = ('JS("%s", "#[#]", this, index)' %
           self.SecureOutputType(element_type));
     elif any(op.id == 'getItem' for op in self._interface.operations):
       indexed_getter = 'this.getItem(index)'
     elif any(op.id == 'item' for op in self._interface.operations):
       indexed_getter = 'this.item(index)'
 
     if indexed_getter:
@@ skipping 448 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)