Fix type error in MultiElementCssClassSet constructor.

Fixes #29901

R=sra@google.com

Change-Id: Idfa1dee3d243ed34c3ca8d1225404143a28746e8
Reviewed-on: https://dart-review.googlesource.com/59340
Reviewed-by: Stephen Adams <sra@google.com>
Commit-Queue: Terry Lucas <terry@google.com>
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 5fb4ceb..a695e1f 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -47632,8 +47632,8 @@
   final List<CssClassSetImpl> _sets;
 
   factory _MultiElementCssClassSet(Iterable<Element> elements) {
-    return new _MultiElementCssClassSet._(
-        elements, elements.map((Element e) => e.classes).toList());
+    return new _MultiElementCssClassSet._(elements,
+        new List<CssClassSetImpl>.from(elements.map((Element e) => e.classes)));
   }
 
   _MultiElementCssClassSet._(this._elementIterable, this._sets);
diff --git a/tests/lib_2/lib_2_dartdevc.status b/tests/lib_2/lib_2_dartdevc.status
index 9cdf0ea..584596a 100644
--- a/tests/lib_2/lib_2_dartdevc.status
+++ b/tests/lib_2/lib_2_dartdevc.status
@@ -79,7 +79,6 @@
 html/custom_elements_23127_test: Skip # Issue 29922
 html/custom_elements_test: Skip # Issue 29922
 html/deferred_multi_app_htmltest: Skip # Issue 29919
-html/element_classes_svg_test: RuntimeError # Issue 29922
 html/element_classes_test: RuntimeError # Issue 29922
 html/fontface_loaded_test: RuntimeError
 html/isolates_test: RuntimeError # Issue 29922
diff --git a/tools/dom/src/dart2js_CssClassSet.dart b/tools/dom/src/dart2js_CssClassSet.dart
index 244e34c..c3394aa 100644
--- a/tools/dom/src/dart2js_CssClassSet.dart
+++ b/tools/dom/src/dart2js_CssClassSet.dart
@@ -15,8 +15,8 @@
   final List<CssClassSetImpl> _sets;
 
   factory _MultiElementCssClassSet(Iterable<Element> elements) {
-    return new _MultiElementCssClassSet._(
-        elements, elements.map((Element e) => e.classes).toList());
+    return new _MultiElementCssClassSet._(elements,
+        new List<CssClassSetImpl>.from(elements.map((Element e) => e.classes)));
   }
 
   _MultiElementCssClassSet._(this._elementIterable, this._sets);