Restore adoptNode and importNode to dart:html

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 ebefdfc6a08663990d5af56637aefb2aa32ce64e..116b28dfc19ca1a2e022b59ab0224e24c0580572 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -6770,6 +6770,10 @@ class Document extends Node  native "Document"
   // 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')
@@ -6888,6 +6892,10 @@ class Document extends Node  native "Document"
   @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;