Rewrite the 'window.onerror' tests.

LayoutTests/fast/events/window-onerror-12-expected.txt

Index: LayoutTests/fast/events/window-onerror-12-expected.txt
diff --git a/LayoutTests/fast/events/window-onerror-12-expected.txt b/LayoutTests/fast/events/window-onerror-12-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..778be293069940dd4950792d10a60c3f894c3d59
--- /dev/null
+++ b/LayoutTests/fast/events/window-onerror-12-expected.txt
@@ -0,0 +1,18 @@
+CONSOLE MESSAGE: line 17: 1
+CONSOLE MESSAGE: line 17: 2
+CONSOLE MESSAGE: line 17: 3
+This test should trigger 'window.onerror' for the exception in the attribute handler, regardless of how it's set.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+window.onerror: "Uncaught TypeError: Cannot call method 'mu' of null" at window-onerror-12.html (Line: 12, Column: 74)
+Returning 'true': the error should not be reported in the console as an unhandled exception.
+window.onerror: "Uncaught TypeError: Cannot call method 'mu' of null" at window-onerror-12.html (Line: 35, Column: 74)
+Returning 'true': the error should not be reported in the console as an unhandled exception.
+window.onerror: "Uncaught TypeError: Cannot call method 'mu' of null" at window-onerror-12.html (Line: 35, Column: 74)
+Returning 'true': the error should not be reported in the console as an unhandled exception.
+PASS successfullyParsed is true
+
+TEST COMPLETE
+Button.  Button 2 Button 3