Remove ui_compositor_image_transport, it has no effect.

chrome/browser/chromeos/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/features.gni")
 import("//build/config/ui.gni")
 import("//extensions/features/features.gni")
 import("//media/media_options.gni")
 import("//printing/features/features.gni")
 import("//third_party/protobuf/proto_library.gni")
@@ skipping 1440 matching lines @@
   } else {
     sources += [
       "printing/fake_cups_print_job_manager.cc",
       "printing/fake_cups_print_job_manager.h",
     ]
   }
 
   if (use_cras) {
     defines = [ "USE_CRAS" ]
   }
-
-  if (ui_compositor_image_transport) {
-    deps += [ "//ui/gl" ]
-  }
 }
 
 static_library("arc_test_support") {
   testonly = true
 
   sources = [
     "arc/test/arc_data_removed_waiter.cc",
     "arc/test/arc_data_removed_waiter.h",
   ]
 }
@@ skipping 319 matching lines @@
     "policy/proto/chrome_device_policy.proto",
     "policy/proto/install_attributes.proto",
   ]
 }
 
 proto_library("attestation_proto") {
   sources = [
     "attestation/attestation_key_payload.proto",
   ]
 }