Make Float{32,64}Array implement List<double>.

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 324 matching lines @@
         declaration,
         GenerateCall,
         IsOptional,
         can_omit_type_check)
 
   def AdditionalImplementedInterfaces(self):
     # TODO: Include all implemented interfaces, including other Lists.
     implements = []
     if self._interface_type_info.is_typed_array():
       element_type = self._interface_type_info.list_item_type()
-      implements.append('List<%s>' % self._DartType(element_type))
-    if self._interface_type_info.list_item_type():
+      implements.append('List<%s>' % element_type)
+    elif self._interface_type_info.list_item_type():
       item_type_info = self._type_registry.TypeInfo(
           self._interface_type_info.list_item_type())
       implements.append('List<%s>' % item_type_info.dart_type())
     return implements
 
   def AddConstructors(self,
       constructors, factory_name, factory_constructor_name):
     """ Adds all of the constructors.
     Arguments:
       constructors - List of the constructors to be added.
@@ skipping 294 matching lines @@
         walk(interface.parents)
       else:
         walk(interface.parents[1:])
     return result
 
   def _DartType(self, type_name):
     return self._type_registry.DartType(type_name)
 
   def _IsPrivate(self, name):
     return name.startswith('_')