Linux: Add xcb FD to glib event loop

ui/base/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/buildflag_header.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
@@ skipping 893 matching lines @@
     deps += [
       "//ui/events",
       "//ui/events/platform",
     ]
   }
 
   if (use_x11 && !is_chromeos) {
     sources += [
       "dragdrop/os_exchange_data_provider_aurax11_unittest.cc",
       "x/selection_requestor_unittest.cc",
+      "x/x11_window_cache_unittest.cc",
     ]
   }
 
   if (is_chromeos) {
     deps += [
       "//chromeos",
       "//ui/events:dom_keycode_converter",
     ]
   }
 
@@ skipping 30 matching lines @@
 if (is_mac) {
   mac_framework_bundle("ui_unittests_framework") {
     testonly = true
     deps = [
       "//ui/resources:ui_test_pak_bundle_data",
     ]
     info_plist = "test/framework-Info.plist"
     output_name = "ui_unittests Framework"
   }
 }