Make *some* version of the Mac GN build work.

ui/base/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")
 
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
 }
@@ skipping 665 matching lines @@
   ]
 
   if (build_ime) {
     sources += [
       "ime/dummy_input_method.cc",
       "ime/dummy_input_method.h",
       "ime/dummy_text_input_client.cc",
       "ime/dummy_text_input_client.h",
     ]
   }
+
+  if (!use_aura) {
+    sources -= [
+      "test/ui_controls_aura.cc",
+    ]
+  }
 }
 
 if (is_android) {
   generate_jni("ui_base_jni_headers") {
     sources = [
       "../android/java/src/org/chromium/ui/base/Clipboard.java",
       "../android/java/src/org/chromium/ui/base/DeviceFormFactor.java",
       "../android/java/src/org/chromium/ui/base/LocalizationUtils.java",
       "../android/java/src/org/chromium/ui/base/ResourceBundle.java",
       "../android/java/src/org/chromium/ui/base/SelectFileDialog.java",
@@ skipping 162 matching lines @@
     ]
   }
 
   if (!is_win || !use_aura) {
     sources -= [
       "view_prop_unittest.cc"
     ]
   }
 
   if (is_mac) {
+    sources -= [
+      "dragdrop/os_exchange_data_provider_aurax11_unittest.cc",
+      "x/selection_requestor_unittest.cc",
+    ]
+
     deps += [
       "//third_party/mozilla",
       #'ui_unittests_bundle',  TODO(GYP)
     ]
   }
 
   if (use_aura || toolkit_views) {
     sources += [
       "dragdrop/os_exchange_data_unittest.cc"
     ]
@@ skipping 19 matching lines @@
       "//ui/chromeos/resources",
       "//ui/chromeos/strings",
       "//ui/chromeos:ui_chromeos",
       "//ui/events:gesture_detection",
       "//ui/message_center:message_center",
     ]
   }
 }
 }
 # TODO(GYP) Mac (ui_unittest_bundle) and Android (ui_unittests_apk).