Implement Model-Driven-Views spec for Dart

tools/dom/templates/html/impl/impl_HTMLDocument.darttemplate

 // 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.
 
 // WARNING: Do not edit - generated code.
 
 part of $LIBRARYNAME;
 
 $(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 $!MEMBERS
@@ skipping 147 matching lines @@
   @SupportedBrowser(SupportedBrowser.SAFARI)
   @Experimental
   Element get pointerLockElement =>
       $dom_webkitPointerLockElement;
 
   @DomName('Document.webkitVisibilityState')
   @SupportedBrowser(SupportedBrowser.CHROME)
   @SupportedBrowser(SupportedBrowser.SAFARI)
   @Experimental
   String get visibilityState => $dom_webkitVisibilityState;
+
+
+$if DART2JS
+  @Creates('Null')  // Set from Dart code; does not instantiate a native type.
+$endif
+  // Note: used to polyfill <template>
+  Document _templateContentsOwner;
 }