Implement KeyboardEvent.repeat attribute

Source/testing/runner/EventSender.cpp

Index: Source/testing/runner/EventSender.cpp
diff --git a/Source/testing/runner/EventSender.cpp b/Source/testing/runner/EventSender.cpp
index 19039272ea17138fe00e8c6f514f5fee93aee17f..985fc1e01e35bd876a85d6286ae65637224902e3 100644
--- a/Source/testing/runner/EventSender.cpp
+++ b/Source/testing/runner/EventSender.cpp
@@ -184,6 +184,8 @@ bool applyKeyModifier(const string& modifierName, WebInputEvent* event)
     } else if (!strcmp(characters, "metaKey")) {
         event->modifiers |= WebInputEvent::MetaKey;
 #endif
+    } else if (!strcmp(characters, "autoRepeat")) {
+        event->modifiers |= WebInputEvent::IsAutoRepeat;
     }
     return isSystemKey;
 }