Allow matches selector to work on current Opera.

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 1952b25c2b78d743cd8c786a623b66608e1e8fbb..08e042dc2ebfab509c2c3b5029889d1150f8f990 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -9668,6 +9668,8 @@ abstract class Element extends Node implements ParentNode, ChildNode native "Ele
       return JS('bool', '#.mozMatchesSelector(#)', this, selectors);
     } else if (JS('bool', '!!#.msMatchesSelector', this)) {
       return JS('bool', '#.msMatchesSelector(#)', this, selectors);
+    } else if (JS('bool', '!!#.oMatchesSelector', this)) {
+      return JS('bool', '#.oMatchesSelector(#)', this, selectors);
     } else {
       throw new UnsupportedError("Not supported on this platform");
     }