chromeos: Remove AshTestBase::SupportsMultipleDisplays

ash/wm/system_modal_container_layout_manager_unittest.cc

 // Copyright (c) 2012 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/wm/system_modal_container_layout_manager.h"
 
 #include <memory>
 
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/wm/container_finder.h"
@@ skipping 566 matching lines @@
     TestWindow::CloseTestWindow(modal_window.release());
     UnblockUserSession();
     // Here we should check the behavior of the locked system modal dialog when
     // unlocked, but such case isn't handled very well right now.
     // See crbug.com/157660
     // TODO(mukai): add the test case when the bug is fixed.
   }
 }
 
 TEST_F(SystemModalContainerLayoutManagerTest, MultiDisplays) {
-  if (!SupportsMultipleDisplays())
-    return;
-
   UpdateDisplay("500x500,500x500");
 
   std::unique_ptr<aura::Window> normal(OpenToplevelTestWindow(false));
   normal->SetBounds(gfx::Rect(100, 100, 50, 50));
 
   aura::Window::Windows root_windows = Shell::GetAllRootWindows();
   EXPECT_EQ(2U, root_windows.size());
   aura::Window* container1 = Shell::GetContainer(
       root_windows[0], ash::kShellWindowId_SystemModalContainer);
   aura::Window* container2 = Shell::GetContainer(
@@ skipping 286 matching lines @@
 
 }  // namespace
 
 TEST_F(SystemModalContainerLayoutManagerTest, BlockAllEvents) {
   InputTestDelegate delegate;
   delegate.RunTest(this);
 }
 
 // Make sure that events are properly blocked in multi displays environment.
 TEST_F(SystemModalContainerLayoutManagerTest, BlockEventsInMultiDisplays) {
-  if (!SupportsMultipleDisplays())
-    return;
-
   UpdateDisplay("500x500, 500x500");
   InputTestDelegate delegate;
   delegate.RunTest(this);
 }
 
 }  // namespace test
 }  // namespace ash