Skip mulitple-dispay tests on win8

ash/display/display_manager.cc

Index: ash/display/display_manager.cc
diff --git a/ash/display/display_manager.cc b/ash/display/display_manager.cc
index 980a38524f5fa0addb98793bec125456efa3a04d..9d03c46f4851142d96bfc821531764c615cc905d 100644
--- a/ash/display/display_manager.cc
+++ b/ash/display/display_manager.cc
@@ -421,6 +421,15 @@ void DisplayManager::UpdateDisplays() {
 
 void DisplayManager::UpdateDisplays(
     const std::vector<DisplayInfo>& updated_display_info_list) {
+#if defined(OS_WIN)
+  if (base::win::GetVersion() >= base::win::VERSION_WIN8) {
+    DCHECK_EQ(1u, updated_display_info_list.size()) <<
+        "Multi display test does not work on Win8 bots. Please "
+        "skip (don't disable) the test using RETURN_IF_WIN8 or "
+        "CONTINUE_IF_WIN8 macro";
+  }
+#endif
+
   DisplayInfoList new_display_info_list = updated_display_info_list;
   std::sort(displays_.begin(), displays_.end(), DisplaySortFunctor());
   std::sort(new_display_info_list.begin(),