Revert "Use WS_POPUP for ash_unittests"

ash/dip_unittest.cc

Index: ash/dip_unittest.cc
diff --git a/ash/dip_unittest.cc b/ash/dip_unittest.cc
index 1df1ec72bd9c67c78d591c690c23fb513368289f..84b230d569692f97e156fceb8a624a3d346fcb73 100644
--- a/ash/dip_unittest.cc
+++ b/ash/dip_unittest.cc
@@ -27,8 +27,15 @@ namespace ash {
 
 typedef ash::test::AshTestBase DIPTest;
 
+#if defined(OS_WIN)
+// Windows/Aura doesn't have DIP support in display yet.
+#define MAYBE_WorkArea DISABLED_WorkArea
+#else
+#define MAYBE_WorkArea WorkArea
+#endif
+
 // Test if the WM sets correct work area under different density.
-TEST_F(DIPTest, WorkArea) {
+TEST_F(DIPTest, MAYBE_WorkArea) {
   ChangeDisplayConfig(1.0f, gfx::Rect(0, 0, 1000, 900));
 
   aura::RootWindow* root = Shell::GetPrimaryRootWindow();