Refined types for most HtmlElement factory constructors

sdk/lib/svg/dartium/svg_dartium.dart

Index: sdk/lib/svg/dartium/svg_dartium.dart
diff --git a/sdk/lib/svg/dartium/svg_dartium.dart b/sdk/lib/svg/dartium/svg_dartium.dart
index 72bce94523a277775d782b5b1e818d3222b048ba..4a98eec6aa20aaa9d6a198867ba3dfabc2f5c61d 100644
--- a/sdk/lib/svg/dartium/svg_dartium.dart
+++ b/sdk/lib/svg/dartium/svg_dartium.dart
@@ -6126,14 +6126,14 @@ class SvgElement extends Element implements GlobalEventHandlers {
   }
 
   String get outerHtml {
-    final container = new Element.tag("div");
+    final container = new DivElement();
     final SvgElement cloned = this.clone(true);
     container.children.add(cloned);
     return container.innerHtml;
   }
 
   String get innerHtml {
-    final container = new Element.tag("div");
+    final container = new DivElement();
     final SvgElement cloned = this.clone(true);
     container.children.addAll(cloned.children);
     return container.innerHtml;