Skip mulitple-dispay tests on win8

ash/wm/window_util_unittest.cc

 // Copyright (c) 2013 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/wm/window_util.h"
 
 #include "ash/screen_ash.h"
 #include "ash/test/ash_test_base.h"
 #include "ui/aura/window.h"
 
 namespace ash {
 
 typedef test::AshTestBase WindowUtilTest;
 
 TEST_F(WindowUtilTest, CenterWindow) {
+  if (!SupportsMultipleDisplays())
+    return;
+
   UpdateDisplay("500x400, 600x400");
   scoped_ptr<aura::Window> window(
       CreateTestWindowInShellWithBounds(gfx::Rect(12, 20, 100, 100)));
   wm::CenterWindow(window.get());
   EXPECT_EQ("200,126 100x100", window->bounds().ToString());
   EXPECT_EQ("200,126 100x100", window->GetBoundsInScreen().ToString());
   window->SetBoundsInScreen(gfx::Rect(600, 0, 100, 100),
                             ScreenAsh::GetSecondaryDisplay());
   wm::CenterWindow(window.get());
   EXPECT_EQ("250,126 100x100", window->bounds().ToString());
   EXPECT_EQ("750,126 100x100", window->GetBoundsInScreen().ToString());
 }
 
 }  // namespace ash