Adds ash_mus_unittests to FYI bot

ash/display/screen_ash_unittest.cc

 // Copyright 2015 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/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ui/aura/test/test_window_delegate.h"
 #include "ui/aura/window.h"
-#include "ui/display/manager/display_manager.h"
 
 namespace ash {
 
-class ScreenAshTest : public test::AshTestBase {
- public:
-  ScreenAshTest() {}
-  ~ScreenAshTest() override {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ScreenAshTest);
-};
+using ScreenAshTest = test::AshTestBase;
 
 // Tests that ScreenAsh::GetWindowAtScreenPoint() returns the correct window on
 // the correct display.
 TEST_F(ScreenAshTest, TestGetWindowAtScreenPoint) {
   UpdateDisplay("200x200,400x400");
 
   aura::test::TestWindowDelegate delegate;
   std::unique_ptr<aura::Window> win1(CreateTestWindowInShellWithDelegate(
       &delegate, 0, gfx::Rect(0, 0, 200, 200)));
 
   std::unique_ptr<aura::Window> win2(CreateTestWindowInShellWithDelegate(
       &delegate, 1, gfx::Rect(200, 200, 100, 100)));
 
   ASSERT_NE(win1->GetRootWindow(), win2->GetRootWindow());
 
   EXPECT_EQ(win1.get(), display::Screen::GetScreen()->GetWindowAtScreenPoint(
                             gfx::Point(50, 60)));
   EXPECT_EQ(win2.get(), display::Screen::GetScreen()->GetWindowAtScreenPoint(
                             gfx::Point(250, 260)));
 }
 
 }  // namespace ash