Add additional test harness error handling to test_controller.

pkg/unittest/test_controller.js

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Test controller logic - used by unit test harness to embed tests in
  * DumpRenderTree.
  */
 
+// Clear the console before every test run - this is Firebug specific code.
+if (typeof console == "object" && typeof console.clear == "function") {
+  console.clear();
+}
+// Set window onerror to make sure that we catch test harness errors across all
+// browsers.
+window.onerror = function (message, url, lineNumber) {

[Siggi Cherem (dart-lang), 2012/10/30 17:36:53]

could this be problematic in non-firefox browsers?

I feel some tension between this line and line 82 below. Should we have some
dynamic test to do one or the other based on the runtime browser, rather than
try to do both always?

[ricow1, 2012/10/31 10:17:53]

This is not firefox only:
http://www.w3.org/wiki/DOM/window.onerror
There seems to be some issues with some browsers where all errors will not be
caught by this. Always catching all errors is important in debugging issues with
out surrounding infrastructure (I would rather have the error twice than not at
all)

+  showErrorAndExit("\n\n" + url + ":" + lineNumber + ":\n" + message + "\n\n");
+  window.postMessage('unittest-suite-external-error', '*');
+};
+
 if (navigator.webkitStartDart) {
   navigator.webkitStartDart();
 }
 
 // testRunner is provided by DRT or WebKit's layout tests.
 // It is not available in selenium tests.
 var testRunner = window.testRunner || window.layoutTestController;
 
 var waitForDone = false;
 
@@ skipping 92 matching lines @@
 function dartMainRunner(main) {
   window.postMessage('dart-calling-main', '*');
   try {
     main();
   } catch (e) {
     window.postMessage('unittest-suite-fail', '*');
     return;
   }
   window.postMessage('dart-main-done', '*');
 }