Add chrome/browser/ui to the GN build.

printing/BUILD.gn

Index: printing/BUILD.gn
diff --git a/printing/BUILD.gn b/printing/BUILD.gn
index b6f37638a2059466de7ec852ccd9f318efca63b8..04b2b9acc1ee0821ca1f05e3985c34a8a6655cda 100644
--- a/printing/BUILD.gn
+++ b/printing/BUILD.gn
@@ -2,6 +2,7 @@
 # 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/ui.gni")
 if (is_mac) {
   import("//build/config/mac/mac_sdk.gni")
@@ -10,8 +11,6 @@ if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
-use_cups = ((is_linux && !is_chromeos) || is_mac)
-
 component("printing") {
   sources = [
     "backend/print_backend.cc",