Fix a type warning for SVGElement.tag.

client/html/src/shared_FactoryProviders.dart

Index: client/html/src/shared_FactoryProviders.dart
diff --git a/client/html/src/shared_FactoryProviders.dart b/client/html/src/shared_FactoryProviders.dart
index 90807d8150711b0723b86c142d84c6a244f559e1..99c90a25eef827ab961618f60f2d4ccd012267b4 100644
--- a/client/html/src/shared_FactoryProviders.dart
+++ b/client/html/src/shared_FactoryProviders.dart
@@ -133,8 +133,11 @@ class _DocumentFragmentFactoryProvider {
 }
 
 class _SVGElementFactoryProvider {
-  factory SVGElement.tag(String tag) =>
-    _document._createElementNS("http://www.w3.org/2000/svg", tag);
+  factory SVGElement.tag(String tag) {
+    final Element temp =
+      _document._createElementNS("http://www.w3.org/2000/svg", tag);
+    return temp;
+  }
 
   factory SVGElement.svg(String svg) {
     Element parentTag;