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

tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate

Index: tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate b/tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate
index 7ee15d1b3ba9aad98b14a1594a7498eda2585fd8..9ad00f61c2c2053f97c229ee85a0ffa0b1dd0b83 100644
--- a/tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate
+++ b/tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate
@@ -404,9 +404,9 @@ $endif
 $if JSINTEROP
   void open(String method, String url, {bool async, String user, String password}) {
     if (async == null && user == null && password == null) {
-      _blink.BlinkXMLHttpRequest.instance.open_Callback_2_(unwrap_jso(this), method, url);
+      _blink.BlinkXMLHttpRequest.instance.open_Callback_2_(this, method, url);
     } else {
-      _blink.BlinkXMLHttpRequest.instance.open_Callback_5_(unwrap_jso(this), method, url, async, user, password);
+      _blink.BlinkXMLHttpRequest.instance.open_Callback_5_(this, method, url, async, user, password);
     }
   }
 $else