Move DisplayUtils methods into gfx::Screen.

ui/ui_unittests.gypi

Index: ui/ui_unittests.gypi
diff --git a/ui/ui_unittests.gypi b/ui/ui_unittests.gypi
index 5b57fb30e8fd4d8a2f61651c54b3107ee24641e9..a550de25bdd11f70e244ce777e056b1d46fb1afb 100644
--- a/ui/ui_unittests.gypi
+++ b/ui/ui_unittests.gypi
@@ -78,6 +78,7 @@
         'gfx/insets_unittest.cc',
         'gfx/rect_unittest.cc',
         'gfx/run_all_unittests.cc',
+        'gfx/screen_unittest.cc',
         'gfx/skbitmap_operations_unittest.cc',
         'gfx/skia_util_unittest.cc',
         'gfx/test_suite.cc',
@@ -176,6 +177,11 @@
             'base/clipboard/clipboard_unittest.cc',
           ],
         }],
+        ['use_aura==1', {
+          'dependencies': [
+            'aura/aura.gyp:aura',
+          ],
+        }],
       ],
     },
   ],