exo: Add minimal support for xdg-shell interface to wayland bindings.

components/exo/wayland/BUILD.gn

 # Copyright 2015 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")
 
 source_set("wayland") {
   sources = [
     "scoped_wl_types.cc",
     "scoped_wl_types.h",
     "server.cc",
     "server.h",
   ]
 
   defines = [ "EXO_IMPLEMENTATION" ]
 
   deps = [
     "//base",
     "//components/exo",
     "//skia",
     "//third_party/wayland:wayland_server",
+    "//third_party/wayland-protocols:xdg_shell_protocol",
   ]
 
   if (use_ozone) {
     deps += [ "//third_party/mesa:wayland_drm_protocol" ]
   }
 }
 
 source_set("unit_tests") {
   testonly = true
 
   sources = [
     "server_unittest.cc",
   ]
 
   deps = [
     ":wayland",
     "//testing/gtest",
     "//third_party/wayland:wayland_client",
   ]
 }