Optimization for Element.innerHtml

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 61dfe4c27f72ba2c40115feb0e99085e206176b8..129d2d928944bbf2b0a3c4d0ad407a6a37f5bfb1 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -9641,6 +9641,7 @@ abstract class Element extends Node implements ParentNode, ChildNode native "Ele
   }
 
   static HtmlDocument _parseDocument;
+  static Range _parseRange;
   static NodeValidatorBuilder _defaultValidator;
   static _ValidatingTreeSanitizer _defaultSanitizer;
 
@@ -9686,6 +9687,7 @@ abstract class Element extends Node implements ParentNode, ChildNode native "Ele
 
     if (_parseDocument == null) {
       _parseDocument = document.implementation.createHtmlDocument('');
+      _parseRange = _parseDocument.createRange();
     }
     var contextElement;
     if (this is BodyElement) {
@@ -9696,9 +9698,8 @@ abstract class Element extends Node implements ParentNode, ChildNode native "Ele
     }
     var fragment;
     if (Range.supportsCreateContextualFragment) {
-      var range = _parseDocument.createRange();
-      range.selectNodeContents(contextElement);
-      fragment = range.createContextualFragment(html);
+      _parseRange.selectNodeContents(contextElement);
+      fragment = _parseRange.createContextualFragment(html);
     } else {
       contextElement._innerHtml = html;