Get rid of the use_glib gn variable.

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")
 import("//ui/events/xkb.gni")
 
 static_library("dom_keycode_converter") {
   sources = [
@@ skipping 112 matching lines @@
     ":dom_keycode_converter",
     ":gesture_detection",
     "//base/third_party/dynamic_annotations",
     "//skia",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 
   if (use_x11) {
     sources += [ "x/events_x.cc" ]
-    configs += [
-      "//build/config/linux:glib",
-      "//build/config/linux:x11",
-    ]
+    configs += [ "//build/config/linux:x11" ]
     deps += [
       "//ui/events/devices",
       "//ui/gfx/x",
     ]
   }
 
   if (use_ozone) {
     sources += [ "ozone/events_ozone.cc" ]
     deps += [ "//ui/events/ozone:events_ozone_layout" ]
   }
@@ skipping 187 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",
     ]
   }
 }