Revert of Removing X11 native_event uses for key events.

ui/events/event_utils.cc

Index: ui/events/event_utils.cc
diff --git a/ui/events/event_utils.cc b/ui/events/event_utils.cc
index 2e3517e3e74249615689fc276b2c2a2e5bf23dc4..c775e10957a447c73b8668a9b67007686102a004 100644
--- a/ui/events/event_utils.cc
+++ b/ui/events/event_utils.cc
@@ -63,8 +63,9 @@
   return event.Pass();
 }
 
+#if defined(OS_LINUX)
 // From third_party/WebKit/Source/web/gtk/WebInputEventFactory.cpp:
-base::char16 GetControlCharacterForKeycode(int windows_key_code, bool shift) {
+uint16 GetControlCharacterForKeycode(int windows_key_code, bool shift) {
   if (windows_key_code >= ui::VKEY_A &&
     windows_key_code <= ui::VKEY_Z) {
     // ctrl-A ~ ctrl-Z map to \x01 ~ \x1A
@@ -107,6 +108,7 @@
   }
   return 0;
 }
+#endif
 
 int RegisterCustomEventType() {
   return ++g_custom_event_types;