ozone: Add initial build support for xkbcommon

ui/events/ozone/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/features.gni")
+import("//build/config/linux/pkg_config.gni")
 import("//build/config/ui.gni")
 
+# Optional system libraries.
+use_xkbcommon = use_ozone
+
+if (use_xkbcommon) {
+  pkg_config("xkbcommon") {
+    packages = [ "xkbcommon" ]
+  }
+}
+
 component("events_ozone") {
   sources = [
     "chromeos/cursor_controller.cc",
     "chromeos/cursor_controller.h",
     "device/device_event.cc",
     "device/device_event.h",
     "device/device_event_observer.h",
     "device/device_manager.cc",
     "device/device_manager.h",
     "device/device_manager_manual.cc",
@@ skipping 13 matching lines @@
   if (!use_udev) {
     sources -= [
       "device/udev/device_manager_udev.cc",
       "device/udev/device_manager_udev.h",
     ]
   }
 
   if (use_ozone_evdev && use_udev) {
     deps += [ "//device/udev_linux" ]
   }
+
+  if (use_xkbcommon) {
+    configs += [ ":xkbcommon" ]
+
+    defines += [ "USE_XKBCOMMON" ]
+  }
 }
 
 config("evdev") {
   defines = [ "USE_EVDEV" ]
 }
 
 config("evdev_gestures") {
   defines = [ "USE_EVDEV_GESTURES" ]
 }
 
@@ skipping 51 matching lines @@
     ]
 
     public_configs += [ ":evdev_gestures" ]
 
     configs += [
       "//build/config/linux:libevdev-cros",
       "//build/config/linux:libgestures",
     ]
   }
 }