Remove ui_compositor_image_transport, it has no effect.

chrome/browser/ui/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/chromecast_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 2102 matching lines @@
       sources += [
         "views/frame/desktop_browser_frame_aura.cc",
         "views/frame/desktop_browser_frame_aura.h",
         "views/message_center/message_center_frame_view.cc",
         "views/message_center/message_center_frame_view.h",
         "views/message_center/web_notification_tray.cc",
         "views/message_center/web_notification_tray.h",
       ]
     }
   }
-  if (ui_compositor_image_transport) {
-    deps += [ "//ui/gl" ]
-  }
   if (use_nss_certs) {
     sources += [
       "crypto_module_delegate_nss.cc",
       "crypto_module_delegate_nss.h",
       "crypto_module_password_dialog_nss.cc",
       "crypto_module_password_dialog_nss.h",
       "webui/options/certificate_manager_handler.cc",
       "webui/options/certificate_manager_handler.h",
       "webui/settings/certificates_handler.cc",
       "webui/settings/certificates_handler.h",
@@ skipping 1397 matching lines @@
       "test/test_confirm_bubble_model.cc",
       "test/test_confirm_bubble_model.h",
     ]
     deps += [ "//chrome/test:test_support_ui" ]
   }
 
   if (enable_extensions) {
     deps += [ "//extensions/browser" ]
   }
 }