Tighten type of 'document' to HtmlDocument

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 795f26ad014c1b3b9693a5957bf1b616fc98ecf0..d06776ab2a0b7468f5bc0ce9839786390be56f6c 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -38,7 +38,7 @@ Window get window => JS('Window', 'window');
 /**
  * The top-level Document object.
  */
-HtmlDocument get document => JS('Document', 'document');
+HtmlDocument get document => JS('HtmlDocument', 'document');
 
 Element query(String selector) => document.query(selector);
 List<Element> queryAll(String selector) => document.queryAll(selector);
@@ -12190,13 +12190,9 @@ class HtmlDocument extends Document native "*HTMLDocument" {
   @DocsEditable
   final Element activeElement;
 
-  @DomName('Document.body')
-  BodyElement get body => $dom_body;
 
   @DomName('Document.body')
-  void set body(BodyElement value) {
-    $dom_body = value;
-  }
+  BodyElement body;
 
   @DomName('Document.caretRangeFromPoint')
   Range caretRangeFromPoint(int x, int y) {