[Chrome OS MD] Draw a 1px separator between 2 tray items

ash/common/system/chromeos/ime_menu/ime_menu_tray_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/common/system/chromeos/ime_menu/ime_menu_tray.h"
 
 #include "ash/common/system/tray/system_tray_notifier.h"
+#include "ash/common/system/view_observer.h"
 #include "ash/common/wm_shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/test_system_tray_delegate.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/events/event.h"
 #include "ui/views/controls/label.h"
 
 using base::UTF8ToUTF16;
 
 namespace ash {
 
 class ImeMenuTrayTest : public test::AshTestBase {
  public:
   ImeMenuTrayTest() {}
   ~ImeMenuTrayTest() override {}
 
   ImeMenuTray* ime_menu_tray() { return ime_menu_tray_.get(); }
 
   // test::AshTestBase:
   void SetUp() override {
     test::AshTestBase::SetUp();
-    ime_menu_tray_.reset(new ImeMenuTray(GetPrimaryShelf()));
+    ViewObserver* view_observer = new ViewObserver();
+    ime_menu_tray_.reset(new ImeMenuTray(GetPrimaryShelf(), view_observer));
   }
 
   void TearDown() override {
     ime_menu_tray_.reset();
     test::AshTestBase::TearDown();
   }
 
  protected:
   // Returns true if the IME menu tray is visible.
   bool IsVisible() { return ime_menu_tray_->visible(); }
@@ skipping 73 matching lines @@
   // If disabling the IME menu feature when the menu tray is activated, the tray
   // element will be deactivated.
   ime_menu_tray()->PerformAction(tap);
   EXPECT_TRUE(IsTrayBackgroundActive());
   WmShell::Get()->system_tray_notifier()->NotifyRefreshIMEMenu(false);
   EXPECT_FALSE(IsVisible());
   EXPECT_FALSE(IsTrayBackgroundActive());
 }
 
 }  // namespace ash