Making readonly fields on interfaces be readonly

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 logging
@@ skipping 786 matching lines @@
           '  }\n',
           TYPE=self._NarrowInputType(element_type))
 
     self.EmitListMixin(self._DartType(element_type))
 
   def EmitAttribute(self, attribute, html_name, read_only):
     if self._HasCustomImplementation(attribute.id):
       return
 
     if IsPureInterface(self._interface.id):
-      self._AddInterfaceAttribute(attribute, html_name)
+      self._AddInterfaceAttribute(attribute, html_name, read_only)
       return
 
     # If the attribute is shadowing, we can't generate a shadowing
     # field (Issue 1633).
     # TODO(sra): _FindShadowedAttribute does not take into account the html
     #  renaming.  we should be looking for another attribute that has the same
     #  html_name.  Two attributes with the same IDL name might not match if one
     #  is renamed.
     (super_attribute, super_attribute_interface) = self._FindShadowedAttribute(
         attribute)
@@ skipping 45 matching lines @@
           RENAME=rename,
           ANNOTATIONS=metadata,
           NAME=html_name,
           TYPE=output_type)
 
   def _AddAttributeUsingProperties(self, attribute, html_name, read_only):
     self._AddRenamingGetter(attribute, html_name)
     if not read_only:
       self._AddRenamingSetter(attribute, html_name)
 
-  def _AddInterfaceAttribute(self, attribute, html_name):
+  def _AddInterfaceAttribute(self, attribute, html_name, read_only):
     self._members_emitter.Emit(
-        '\n  $TYPE $NAME;'
+        '\n  $QUALIFIER$TYPE $NAME;'
         '\n',
+        QUALIFIER='final ' if read_only else '',
         NAME=html_name,
         TYPE=self.SecureOutputType(attribute.type.id))
 
   def _AddRenamingGetter(self, attr, html_name):
 
     conversion = self._OutputConversion(attr.type.id, attr.id)
     if conversion:
       return self._AddConvertingGetter(attr, html_name, conversion)
     return_type = self.SecureOutputType(attr.type.id)
     native_type = self._NarrowToImplementationType(attr.type.id)
@@ skipping 351 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)