Revert CLs by gram 12515-12526.

pkg/unittest/html_enhanced_config.dart

Index: pkg/unittest/html_enhanced_config.dart
===================================================================
--- pkg/unittest/html_enhanced_config.dart	(revision 12526)
+++ pkg/unittest/html_enhanced_config.dart	(working copy)
@@ -21,7 +21,6 @@
 
   // TODO(rnystrom): Get rid of this if we get canonical closures for methods.
   EventListener _onErrorClosure;
-  EventListener _onMessageClosure;
 
   void onInit() {
     //initialize and load CSS
@@ -38,18 +37,12 @@
 
     _onErrorClosure =
         (e) => handleExternalError(e, '(DOM callback has errors)');
-    _onMessageClosure = (m) {
-      if (m.data == 'unittest-suite-external-error') {
-        handleExternalError('<unknown>', '(external error detected)');
-      }
-    };
   }
 
   void onStart() {
     window.postMessage('unittest-suite-wait-for-done', '*');
     // Listen for uncaught errors.
     window.on.error.add(_onErrorClosure);
-    window.on.error.add(_onMessageClosure);
   }
 
   void onTestResult(TestCase testCase) {}
@@ -57,7 +50,6 @@
   void onDone(int passed, int failed, int errors, List<TestCase> results,
       String uncaughtError) {
     window.on.error.remove(_onErrorClosure);
-    window.on.error.remove(_onMessageClosure);
 
     _showInteractiveResultsInPage(passed, failed, errors, results,
         _isLayoutTest, uncaughtError);