ozone: Add initial build support for xkbcommon

ui/events/ozone/BUILD.gn

Index: ui/events/ozone/BUILD.gn
diff --git a/ui/events/ozone/BUILD.gn b/ui/events/ozone/BUILD.gn
index e623e636ba3d7cbb9a7ae8730190a6f991c3d21b..fd98f6d8732498d9edf48b3c39f821d7be90dc7e 100644
--- a/ui/events/ozone/BUILD.gn
+++ b/ui/events/ozone/BUILD.gn
@@ -3,8 +3,18 @@
 # 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",
@@ -38,6 +48,12 @@ component("events_ozone") {
   if (use_ozone_evdev && use_udev) {
     deps += [ "//device/udev_linux" ]
   }
+
+  if (use_xkbcommon) {
+    configs += [ ":xkbcommon" ]
+
+    defines += [ "USE_XKBCOMMON" ]
+  }
 }
 
 config("evdev") {