Revise ui::DomKey to unify character and non-character codes.

ui/events/ozone/layout/keyboard_layout_engine.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_OZONE_PUBLIC_KEYBOARD_LAYOUT_ENGINE_H_
 #define UI_OZONE_PUBLIC_KEYBOARD_LAYOUT_ENGINE_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
+#include "ui/events/keycodes/dom/dom_key.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/events/ozone/layout/events_ozone_layout_export.h"
 
 namespace ui {
 
 enum class DomCode;
-enum class DomKey;
 
 // A KeyboardLayoutEngine provides a platform-independent interface to
 // key mapping. Key mapping provides a meaning (DomKey and character,
 // and optionally Windows key code) for a physical key press (DomCode
 // and modifier flags).
 //
 // This interface does not expose individual layouts because it must support
 // platforms that only provide for one active system layout, and/or platforms
 // where layouts have no accessible representation.
 class EVENTS_OZONE_LAYOUT_EXPORT KeyboardLayoutEngine {
@@ skipping 31 matching lines @@
   // to 0, and *key_code to VKEY_UNKNOWN.
   //
   // Returns false if it cannot determine the meaning (and cannot determine
   // that there is none); in this case it does not set any of the output
   // parameters.
   //
   // TODO(kpschoedel): remove the platform_keycode output. crbug.com/442757
   virtual bool Lookup(DomCode dom_code,
                       int event_flags,
                       DomKey* dom_key,
-                      base::char16* character,
                       KeyboardCode* key_code,
                       uint32* platform_keycode) const = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PUBLIC_KEYBOARD_LAYOUT_ENGINE_H_