Make direct calls to _nativeIndexedGetter in "get last" "get first" "get single" instead of calling…

tools/dom/scripts/htmldartgenerator.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
 from generator import AnalyzeOperation, ConstantOutputOrder, \
@@ skipping 617 matching lines @@
              NAME=method_name,
              PARAMS=operation.ParametersDeclaration(self._DartType))
 
   def EmitListMixin(self, element_name):
     # TODO(sra): Use separate mixins for mutable implementations of List<T>.
     # TODO(sra): Use separate mixins for typed array implementations of List<T>.
     template_file = 'immutable_list_mixin.darttemplate'
     has_length = False
     has_length_setter = False
 
+    def _HasExplicitIndexedGetter(self):
+      return any(op.id == 'getItem' for op in self._interface.operations)
+
+    def _HasCustomIndexedGetter(self):
+      return 'CustomIndexedGetter' in self._interface.ext_attrs
+
+    def _HasNativeIndexedGetter(self):
+      return not (_HasCustomIndexedGetter(self) or _HasExplicitIndexedGetter(self))
+
+    if _HasExplicitIndexedGetter(self):
+      getter_name = 'getItem'
+    else:
+      getter_name = '_nativeIndexedGetter'
+
     for attr in self._interface.attributes:
       if attr.id == 'length':
         has_length = True
         has_length_setter = not attr.is_read_only
 
     has_num_items = any(attr.id == 'numberOfItems'
         for attr in self._interface.attributes)
 
     template = self._template_loader.Load(
         template_file,
         {
           'DEFINE_LENGTH_AS_NUM_ITEMS': not has_length and has_num_items,
           'DEFINE_LENGTH_SETTER': not has_length_setter,
+          'USE_NATIVE_INDEXED_GETTER': _HasNativeIndexedGetter(self) or _HasExplicitIndexedGetter(self),
         })
-    self._members_emitter.Emit(template, E=element_name)
+    self._members_emitter.Emit(template, E=element_name, GETTER=getter_name)
 
   def SecureOutputType(self, type_name, is_dart_type=False,
       can_narrow_type=False):
     """ Converts the type name to the secure type name for return types.
     Arguments:
       can_narrow_type - True if the output type can be narrowed further than
         what would be accepted for input, used to narrow num APIs down to double
         or int.
     """
     if is_dart_type:
@@ skipping 13 matching lines @@
 
   def SecureBaseName(self, type_name):
     if type_name in _secure_base_types:
       return _secure_base_types[type_name]
 
   def _DartType(self, type_name):
     return self._type_registry.DartType(type_name)
 
   def _TypeInfo(self, type_name):
     return self._type_registry.TypeInfo(type_name)