Converting Element.client*, offset* and Screen.avail* over to Rects

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

 // Copyright (c) 2013, 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.
 
 part of $LIBRARYNAME;
 
 @DocsEditable
 $(ANNOTATIONS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 
-  @DomName('HTMLTableSectionElement.rows')
-  List<TableRowElement> get rows =>
-    new _WrappedList<TableRowElement>($dom_rows);
-
-  TableRowElement addRow() {
-    return insertRow(-1);
-  }
-
-  TableRowElement insertRow(int index) => $dom_insertRow(index);
-
+  @DomName('Screen.availHeight')
+  @DomName('Screen.availLeft')
+  @DomName('Screen.availTop')
+  @DomName('Screen.availWidth')
+  Rect get available => new Rect($dom_availLeft, $dom_availTop, $dom_availWidth,
+      $dom_availHeight);
 $!MEMBERS}