Implement all system menu title row buttons for Ash MD

ash/common/system/tray/tray_utils.h

Index: ash/common/system/tray/tray_utils.h
diff --git a/ash/common/system/tray/tray_utils.h b/ash/common/system/tray/tray_utils.h
index 5d51783217443c46b2fff48f895eaf5a7b8c6e46..d82241bee8fcd9192237bfecf56b57e072c3e15f 100644
--- a/ash/common/system/tray/tray_utils.h
+++ b/ash/common/system/tray/tray_utils.h
@@ -7,6 +7,7 @@
 
 #include <vector>
 
+#include "ash/common/login_status.h"
 #include "ash/public/cpp/shelf_types.h"
 #include "base/strings/string16.h"
 
@@ -36,6 +37,11 @@ void GetAccessibleLabelFromDescendantViews(
     views::View* view,
     std::vector<base::string16>& out_labels);
 
+// Returns true if it is possible to open WebUI settings in a browser window,
+// i.e., the user is logged in, not on the lock screen, and not in a secondary
+// account flow.
+bool CanOpenWebUISettings(LoginStatus status);
+
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_TRAY_UTILS_H_