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 6f7854ef914a91336548192151988f02fc8dddb8..811f06906208acee8576a0d092aaa5249cde55b6 100644
--- a/ash/common/system/tray/system_tray_unittest.cc
+++ b/ash/common/system/tray/system_tray_unittest.cc
@@ -32,6 +32,7 @@
 #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"
@@ -644,5 +645,9 @@ 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