Added some more documentation to top level Window.

sdk/lib/html/dart2js/html_dart2js.dart

 /// The Dart HTML library.
 ///
 /// For examples, see
 /// [Dart HTML5 Samples](https://github.com/dart-lang/dart-html5-samples)
 /// on Github.
 library dart.dom.html;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_collection-dev' hide Symbol, deprecated;
@@ skipping 20 matching lines @@
 // Auto-generated dart:html library.
 
 
 // Not actually used, but imported since dart:html can generate these objects.
 
 
 
 
 
 /**
- * The top-level Window object.
+ * Top-level container for a web page, which is usually a browser tab or window.
+ *
+ * Each web page loaded in the browser has its own [Window], which is a
+ * container for the web page.
+ *
+ * If the web page has any `<iframe>` elements, then each `iframe` has its own

[Kathy Walrath, 2013/07/11 22:59:45]

I would use either iframe or `<iframe>` (never `iframe`), but otherwise lgtm.

+ * [Window] object, which is accessible only to that `iframe`.
+ *
+ * See also:
+ *
+ *   * [Window](https://developer.mozilla.org/en-US/docs/Web/API/window) from MDN.
  */
 Window get window => JS('Window', 'window');
 
 /**
- * The top-level Document object.
+ * Root node for all content in a web page.
  */
 HtmlDocument get document => JS('HtmlDocument', 'document');
 
 Element query(String selector) => document.query(selector);
 ElementList queryAll(String selector) => document.queryAll(selector);
 
 // Workaround for tags like <cite> that lack their own Element subclass --
 // Dart issue 1990.
 class _HTMLElement extends Element native "HTMLElement" {
 }
@@ skipping 29384 matching lines @@
       _position = nextPosition;
       return true;
     }
     _current = null;
     _position = _array.length;
     return false;
   }
 
   T get current => _current;
 }