[KeyboardEvent] Add embedder APIs to translate between Dom |key| enum and strings

ui/events/event.h

Index: ui/events/event.h
diff --git a/ui/events/event.h b/ui/events/event.h
index 49d650a5d70bb0bb066063c19a2630efc3a59eac..34b5f244833238c1bbc9f90b1fb2e1e5f66ac345 100644
--- a/ui/events/event.h
+++ b/ui/events/event.h
@@ -738,6 +738,9 @@ class EVENTS_EXPORT KeyEvent : public Event {
   // Returns the DOM .key (layout meaning) for a keystroke event.
   DomKey GetDomKey() const;
 
+  // Returns either DomKey or Unicode value + DomKey::CHARACTER.
+  int GetDomKeyOrCharacter() const;
+
   // Normalizes flags_ so that it describes the state after the event.
   // (Native X11 event flags describe the state before the event.)
   void NormalizeFlags();