Skip DisplayManagerTest.ScreenAfterShutdown on win8 (which doesn't support multiple dislpays on ash)

ash/display/display_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/display/display_manager.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/display/display_layout_store.h"
 #include "ash/screen_util.h"
 #include "ash/shell.h"
@@ skipping 1191 matching lines @@
     std::vector<gfx::Display> all = screen->GetAllDisplays();
     EXPECT_EQ("500x300", all[0].size().ToString());
     EXPECT_EQ("800x400", all[1].size().ToString());
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ScreenShutdownTest);
 };
 
 TEST_F(DisplayManagerTest, ScreenAfterShutdown) {
+  if (!SupportsMultipleDisplays())
+    return;
   UpdateDisplay("500x300,800x400");
 }
 
 }  // namespace internal
 }  // namespace ash