Revert of Add libgtk3ui to gn_all

BUILD.gn

 # Copyright (c) 2013 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.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 339 matching lines @@
       "//ash:ash_shell_with_content",
       "//ash:ash_unittests",
       "//ui/app_list:app_list_unittests",
       "//ui/app_list/presenter:app_list_presenter_unittests",
       "//ui/aura:aura_unittests",
       "//ui/aura:demo",
       "//ui/wm:wm_unittests",
     ]
   }
 
-  if (is_linux && !is_chromeos && !is_chromecast) {
-    # TODO(thomasanderson): Remove this once we build using
-    # GTK3 by default. (crbug.com/132847, crbug.com/79722)
-    deps += [ "//chrome/browser/ui/libgtkui:libgtk3ui" ]
-  }
-
   if (use_ozone) {
     deps += [ "//ui/ozone" ]
   }
 
   if (use_x11) {
     deps += [ "//tools/xdisplaycheck" ]
   }
 
   if (enable_configuration_policy) {
     deps += [ "//components/policy:policy_templates" ]
@@ skipping 782 matching lines @@
       "//ui/display:display_unittests",
       "//ui/events:events_unittests",
       "//ui/gfx:gfx_unittests",
       "//ui/gl:gl_unittests",
       "//ui/keyboard:keyboard_unittests",
       "//ui/touch_selection:ui_touch_selection_unittests",
       "//url:url_unittests",
     ]
   }
 }