Convert chromeos::EventRewriter to a ui::EventRewriter

ui/events/keycodes/keyboard_code_conversion_x.h

Index: ui/events/keycodes/keyboard_code_conversion_x.h
diff --git a/ui/events/keycodes/keyboard_code_conversion_x.h b/ui/events/keycodes/keyboard_code_conversion_x.h
index ff34ba1358d21c49a69c00ea1181a7896a0e7691..ea347569fb588710e1bdba112b166d054b046d94 100644
--- a/ui/events/keycodes/keyboard_code_conversion_x.h
+++ b/ui/events/keycodes/keyboard_code_conversion_x.h
@@ -17,6 +17,12 @@ EVENTS_BASE_EXPORT KeyboardCode KeyboardCodeFromXKeyEvent(XEvent* xev);
 
 EVENTS_BASE_EXPORT KeyboardCode KeyboardCodeFromXKeysym(unsigned int keysym);
 
+// Returns ui:EF_ flags associated with an X11 Keysym, where the
+// ui::KeyboardCode alone is not sufficient to characterize it.
+// Currently used to distinguish numpad editing keys from their
+// cursor-block equivalents.
+EVENTS_BASE_EXPORT int EventFlagsFromXKeysym(unsigned int keysym);
+
 EVENTS_BASE_EXPORT const char* CodeFromXEvent(XEvent* xev);
 
 // Returns a character on a standard US PC keyboard from an XEvent.