Remove now-unnecessary wrappers around gfx::Screen::GetScreen()

ash/root_window_controller_unittest.cc

Index: ash/root_window_controller_unittest.cc
diff --git a/ash/root_window_controller_unittest.cc b/ash/root_window_controller_unittest.cc
index cd8bcc492f64e3c751fdea694b12bee2b90d78b1..4d1c8635fcc8827bdfa227403c8eacbde2d9458d 100644
--- a/ash/root_window_controller_unittest.cc
+++ b/ash/root_window_controller_unittest.cc
@@ -830,19 +830,19 @@ TEST_F(VirtualKeyboardRootWindowControllerTest, RestoreWorkspaceAfterLogin) {
       root_window->bounds(), 100));
   keyboard_window->Show();
 
-  gfx::Rect before = ash::Shell::GetScreen()->GetPrimaryDisplay().work_area();
+  gfx::Rect before = gfx::Screen::GetScreen()->GetPrimaryDisplay().work_area();
 
   // Notify keyboard bounds changing.
   controller->NotifyKeyboardBoundsChanging(keyboard_container->bounds());
 
   if (!keyboard::IsKeyboardOverscrollEnabled()) {
-    gfx::Rect after = ash::Shell::GetScreen()->GetPrimaryDisplay().work_area();
+    gfx::Rect after = gfx::Screen::GetScreen()->GetPrimaryDisplay().work_area();
     EXPECT_LT(after, before);
   }
 
   // Mock a login user profile change to reinitialize the keyboard.
   ash::Shell::GetInstance()->OnLoginUserProfilePrepared();
-  EXPECT_EQ(ash::Shell::GetScreen()->GetPrimaryDisplay().work_area(), before);
+  EXPECT_EQ(gfx::Screen::GetScreen()->GetPrimaryDisplay().work_area(), before);
 }
 
 // Ensure that system modal dialogs do not block events targeted at the virtual