sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index f3719d3094736dc51ca1f3766032d4742d90e9ba..bd9c154521c1eedd42e8c94e6883daeea1b53a4d 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -32769,8 +32769,8 @@ class _ElementAttributeMap extends _AttributeMap {
     return _element.$dom_getAttribute(key);
   }
 
-  void operator []=(String key, value) {
-    _element.$dom_setAttribute(key, '$value');
+  void operator []=(String key, String value) {
+    _element.$dom_setAttribute(key, value);
   }
 
   String remove(String key) {
@@ -32806,8 +32806,8 @@ class _NamespacedAttributeMap extends _AttributeMap {
     return _element.$dom_getAttributeNS(_namespace, key);
   }
 
-  void operator []=(String key, value) {
-    _element.$dom_setAttributeNS(_namespace, key, '$value');
+  void operator []=(String key, String value) {
+    _element.$dom_setAttributeNS(_namespace, key, value);
   }
 
   String remove(String key) {
@@ -32846,8 +32846,8 @@ class _DataAttributeMap implements Map<String, String> {
 
   String operator [](String key) => $dom_attributes[_attr(key)];
 
-  void operator []=(String key, value) {
-    $dom_attributes[_attr(key)] = '$value';
+  void operator []=(String key, String value) {
+    $dom_attributes[_attr(key)] = value;
   }
 
   String putIfAbsent(String key, String ifAbsent()) =>