Test tidying: use "escape" and "backspace" with eventSender.keyDown()

LayoutTests/editing/deleting/delete-ligature-003.html

Index: LayoutTests/editing/deleting/delete-ligature-003.html
diff --git a/LayoutTests/editing/deleting/delete-ligature-003.html b/LayoutTests/editing/deleting/delete-ligature-003.html
index 0cea78f56192f7009d0c9a1aae1e49dc66c96d6b..07a291e5ea6388d8d3f2c56ebe9395e296e24321 100644
--- a/LayoutTests/editing/deleting/delete-ligature-003.html
+++ b/LayoutTests/editing/deleting/delete-ligature-003.html
@@ -10,7 +10,7 @@
         }
         function sendBackwardDeleteKey() {
             if (window.eventSender)
-                eventSender.keyDown(String.fromCharCode(0x0008), null);
+                eventSender.keyDown("backspace", null);
         }
         function runTestOn(platform) {
             var testarea = document.getElementById("test");