Aura needs event translation for Mac

ui/base/keycodes/keyboard_code_conversion_mac.h

Index: ui/base/keycodes/keyboard_code_conversion_mac.h
diff --git a/ui/base/keycodes/keyboard_code_conversion_mac.h b/ui/base/keycodes/keyboard_code_conversion_mac.h
index 74499b7d04079e0e03764f949e84bc1410eda445..ef2bb5d6a1dc100e31bc8c0b6538952d449af675 100644
--- a/ui/base/keycodes/keyboard_code_conversion_mac.h
+++ b/ui/base/keycodes/keyboard_code_conversion_mac.h
@@ -24,13 +24,18 @@ namespace ui {
 // |characterIgnoringModifiers|.
 // -1 will be returned if the keycode can't be converted.
 // This function is mainly for simulating keyboard events in unit tests.
-// See third_party/WebKit/Source/WebKit/chromium/src/mac/WebInputEventFactory.mm for
-// reverse conversion.
+// See |KeyboardCodeFromNSEvent| for reverse conversion.
 UI_EXPORT int MacKeyCodeForWindowsKeyCode(KeyboardCode keycode,
                                           NSUInteger flags,
                                           unichar* character,
                                           unichar* characterIgnoringModifiers);
 
+// This implementation cribbed from:
+//   third_party/WebKit/Source/WebKit/chromium/src/mac/WebInputEventFactory.mm
+// Converts |event| into a |KeyboardCode|.  The mapping is not direct as the Mac
+// has a different notion of key codes.
+UI_EXPORT KeyboardCode KeyboardCodeFromNSEvent(NSEvent* event);
+
 } // namespace ui
 
 #endif  // UI_BASE_KEYCODES_KEYBOARD_CODE_CONVERSION_MAC_H_