Modify blink type map to finalize lazily

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 1238 matching lines @@
     for path in sorted(self._paths):
       relpath = os.path.relpath(path, library_file_dir)
       imports_emitter.Emit(
           "part '$PATH';\n", PATH=massage_path(relpath))
 
     if map_emitter:
       items = self._typeMap.items()
       items.sort()
       for (idl_name, dart_name) in items:
         map_emitter.Emit(
-          "  '$IDL_NAME': $DART_NAME,\n",
+          "  '$IDL_NAME': () => $DART_NAME,\n",
           IDL_NAME=idl_name,
           DART_NAME=dart_name)
       
 
 # ------------------------------------------------------------------------------
 
 class DartLibraries():
   def __init__(self, libraries, template_loader, library_type, output_dir):
     self._libraries = {}
     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 AddTypeEntry(self, library_name, idl_name, dart_name):
     self._libraries[library_name].AddTypeEntry(idl_name, dart_name)
 
   def Emit(self, emitter, auxiliary_dir):
     for lib in self._libraries.values():
       lib.Emit(emitter, auxiliary_dir)