Skip mulitple-dispay tests on win8

ash/wm/system_modal_container_layout_manager_unittest.cc

Index: ash/wm/system_modal_container_layout_manager_unittest.cc
diff --git a/ash/wm/system_modal_container_layout_manager_unittest.cc b/ash/wm/system_modal_container_layout_manager_unittest.cc
index 15107a4f266c48b2239567327c7b87e905f6bbcd..35891ef3d0b499fba1f4710ec77483bb59c6cd6d 100644
--- a/ash/wm/system_modal_container_layout_manager_unittest.cc
+++ b/ash/wm/system_modal_container_layout_manager_unittest.cc
@@ -437,14 +437,10 @@ TEST_F(SystemModalContainerLayoutManagerTest, ShowNormalBackgroundOrLocked) {
   // TODO(mukai): add the test case when the bug is fixed.
 }
 
-#if defined(OS_WIN)
-// Multiple displays are not supported on Windows Ash. http://crbug.com/165962
-#define MAYBE_MultiDisplays DISABLED_MultiDisplays
-#else
-#define MAYBE_MultiDisplays MultiDisplays
-#endif
+TEST_F(SystemModalContainerLayoutManagerTest, MultiDisplays) {
+  if (!SupportsMultipleDisplays())
+    return;
 
-TEST_F(SystemModalContainerLayoutManagerTest, MAYBE_MultiDisplays) {
   UpdateDisplay("500x500,500x500");
 
   scoped_ptr<aura::Window> normal(OpenToplevelTestWindow(false));