Optimize dartium dart:html bindings so real world application performance is acceptable. Improves d…

sdk/lib/html/html_common/conversions_dart2js.dart

Index: sdk/lib/html/html_common/conversions_dart2js.dart
diff --git a/sdk/lib/html/html_common/conversions_dart2js.dart b/sdk/lib/html/html_common/conversions_dart2js.dart
index b7f3d7cbbccfd7604bb0b754bdbab6a95468147a..b5a1064554f66a1a3824700981c4e94a0a5cf06b 100644
--- a/sdk/lib/html/html_common/conversions_dart2js.dart
+++ b/sdk/lib/html/html_common/conversions_dart2js.dart
@@ -91,9 +91,3 @@ Future convertNativePromiseToDartFuture(promise) {
   var newPromise = JS('', '#.then(#)["catch"](#)', promise, then, error);
   return completer.future;
 }
-
-/// Wrap a JS object with an instance of the matching dart:html class. Used only in Dartium.
-wrap_jso(jsObject) => jsObject;
-
-/// Find the underlying JS object for a dart:html Dart object.
-unwrap_jso(dartClass_instance) => dartClass_instance;