Updated top level docs for Window.

tools/dom/src/CrossFrameTypes.dart

 // 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.
 
 part of html;
 
 /**
- * An object representing the top-level context object for web scripting.
+ * Top-level container for a browser tab or window.
  *
- * In a web browser, a [Window] object represents the actual browser window.
- * In a multi-tabbed browser, each tab has its own [Window] object. A [Window]
- * is the container that displays a [Document]'s content. All web scripting
- * happens within the context of a [Window] object.
+ * In a web browser, a [WindowBase] object represents any browser window.  This
+ * abstract class contains the state of the window and its relation to other
+ * windows, such as which window opened it.
  *
  * **Note:** This class represents any window, whereas [Window] is
- * used to access the properties and content of the current window.
+ * used to access the properties and content of the current window or tab.
  *
- * See also:
+ * ## Other resources
  *
  * * [DOM Window](https://developer.mozilla.org/en-US/docs/DOM/window) from MDN.
  * * [Window](http://www.w3.org/TR/Window/) from the W3C.
  */
 abstract class WindowBase implements EventTarget {
   // Fields.
 
   /**
    * The current location of this window.
    *
@@ skipping 91 matching lines @@
 
 abstract class LocationBase {
   void set href(String val);
 }
 
 abstract class HistoryBase {
   void back();
   void forward();
   void go(int distance);
 }