views::Separator cleanup.

ash/common/system/tray/system_tray_unittest.cc

Index: ash/common/system/tray/system_tray_unittest.cc
diff --git a/ash/common/system/tray/system_tray_unittest.cc b/ash/common/system/tray/system_tray_unittest.cc
index 0da4a4cb1fa4f257fa660d71f5b93416b72770cb..092c4c6ee1717163da852cb1a7b4a105e9aa90d1 100644
--- a/ash/common/system/tray/system_tray_unittest.cc
+++ b/ash/common/system/tray/system_tray_unittest.cc
@@ -31,6 +31,7 @@
 #include "ui/events/test/event_generator.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
+#include "ui/views/controls/separator.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
@@ -580,5 +581,9 @@ TEST_F(SystemTrayTest, SystemTrayHeightWithBubble) {
   EXPECT_EQ(0, notification_tray->tray_bubble_height_for_test());
 }
 
+TEST_F(SystemTrayTest, SeparatorThickness) {
+  EXPECT_EQ(kSeparatorWidth, views::Separator::kThickness);
+}
+
 }  // namespace test
 }  // namespace ash