Adding "dispatchEvent" which is defined in Mozilla on the window.

Issue: 3226



git-svn-id: https://google-web-toolkit.googlecode.com/svn/releases/1.6@4401 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/dev/core/src/com/google/gwt/dev/js/ast/JsRootScope.java b/dev/core/src/com/google/gwt/dev/js/ast/JsRootScope.java
index 864734a..62b564b 100644
--- a/dev/core/src/com/google/gwt/dev/js/ast/JsRootScope.java
+++ b/dev/core/src/com/google/gwt/dev/js/ast/JsRootScope.java
@@ -95,8 +95,8 @@
         "onunload",
 
         // Common browser-defined identifiers not defined in ECMAScript
-        "window", "event", "external", "navigator", "screen", "Debug",
-        "Enumerator", "Global", "Image", "ActiveXObject", "VBArray",
+        "window", "dispatchEvent", "event", "external", "navigator", "screen",
+        "Debug", "Enumerator", "Global", "Image", "ActiveXObject", "VBArray",
         "Components",
 
         // Functions commonly defined on Object