Skip DisplayManagerTest.ScreenAfterShutdown on win8 (which doesn't support...

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

BUG=NONE
RDANBEAM

R=dbeam@chromium.org

Review URL: https://codereview.chromium.org/142003003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245578 0039d316-1c4b-4281-b951-d872f2087c98

ash/display/display_manager_unittest.cc

@@ -1209,6 +1209,8 @@ class ScreenShutdownTest : public test::AshTestBase {
 };
 
 TEST_F(DisplayManagerTest, ScreenAfterShutdown) {
+  if (!SupportsMultipleDisplays())
+    return;
   UpdateDisplay("500x300,800x400");
 }