Set ui::KeyEvent::key_ (DOM Level 3 key) under X11.

ui/events/BUILD.gn

 # 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.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 static_library("dom4_keycode_converter") {
   sources = [
     "keycodes/dom3/dom_code.h",
@@ skipping 58 matching lines @@
 
     sources += [
       "keycodes/keyboard_code_conversion_x.cc",
       "keycodes/keyboard_code_conversion_x.h",
       "x/keysym_to_unicode.cc",
       "x/keysym_to_unicode.h",
     ]
 
     deps += [ "//ui/gfx/x" ]
   }
+
+  if (use_x11 || use_ozone) {
+    sources += [
+      "keycodes/keyboard_code_conversion_xkb.cc",
+      "keycodes/keyboard_code_conversion_xkb.h",
+      "keycodes/xkb_keysym.h",
+    ]
+  }
 }
 
 component("events") {
   sources = [
     "cocoa/cocoa_event_utils.h",
     "cocoa/cocoa_event_utils.mm",
     "cocoa/events_mac.mm",
     "event.cc",
     "event.h",
     "event_dispatcher.cc",
@@ skipping 274 matching lines @@
 if (is_nacl) {
   source_set("latency_info") {
     sources = [
       "ipc/latency_info_param_traits.cc",
       "ipc/latency_info_param_traits.h",
       "latency_info.cc",
       "latency_info.h",
     ]
   }
 }