Fix 'gn check' errors in //ui/* targets.

ui/views_content_client/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")
 
 component("views_content_client") {
   testonly = true
   sources = [
     "views_content_browser_client.cc",
@@ skipping 32 matching lines @@
       "views_content_client_main_parts_aura.cc",
       "views_content_client_main_parts_aura.h",
     ]
 
     if (!is_chromeos) {
       sources += [ "views_content_client_main_parts_desktop_aura.cc" ]
     }
 
     deps += [ "//ui/aura" ]
   }
+
+  if (is_chromeos) {
+    deps += [
+      "//ui/aura:test_support",
+      "//ui/wm:test_support",
+    ]
+  }
 }