Restore adoptNode and importNode to dart:html

sdk/lib/html/dart2js/html_dart2js.dart

 /// The Dart HTML library.
 library dart.dom.html;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_collection-dev' hide Symbol;
 import 'dart:html_common';
 import 'dart:indexed_db';
 import 'dart:isolate';
 import 'dart:json' as json;
@@ skipping 6752 matching lines @@
 
   @JSName('webkitVisibilityState')
   @DomName('Document.webkitVisibilityState')
   @DocsEditable
   @SupportedBrowser(SupportedBrowser.CHROME)
   @SupportedBrowser(SupportedBrowser.SAFARI)
   @Experimental
   // https://dvcs.w3.org/hg/webperf/raw-file/tip/specs/PageVisibility/Overview.html#dom-document-visibilitystate
   final String $dom_webkitVisibilityState;
 
+  @DomName('Document.adoptNode')
+  @DocsEditable
+  Node adoptNode(Node source) native;
+
   @JSName('caretRangeFromPoint')
   /// Use the [Range] constructor instead.
   @DomName('Document.caretRangeFromPoint')
   @DocsEditable
   // http://www.w3.org/TR/2009/WD-cssom-view-20090804/#dom-documentview-caretrangefrompoint
   @Experimental
   Range $dom_caretRangeFromPoint(int x, int y) native;
 
   @JSName('createCDATASection')
   @DomName('Document.createCDATASection')
@@ skipping 98 matching lines @@
   @Returns('NodeList')
   @Creates('NodeList')
   List<Node> getElementsByName(String elementName) native;
 
   @DomName('Document.getElementsByTagName')
   @DocsEditable
   @Returns('NodeList')
   @Creates('NodeList')
   List<Node> getElementsByTagName(String tagname) native;
 
+  @DomName('Document.importNode')
+  @DocsEditable
+  Node importNode(Node importedNode, [bool deep]) native;
+
   @DomName('Document.queryCommandEnabled')
   @DocsEditable
   bool queryCommandEnabled(String command) native;
 
   @DomName('Document.queryCommandIndeterm')
   @DocsEditable
   bool queryCommandIndeterm(String command) native;
 
   @DomName('Document.queryCommandState')
   @DocsEditable
@@ skipping 22696 matching lines @@
       _position = nextPosition;
       return true;
     }
     _current = null;
     _position = _array.length;
     return false;
   }
 
   T get current => _current;
 }