Validate incoming window properties.

ash/public/cpp/shelf_types.h

Index: ash/public/cpp/shelf_types.h
diff --git a/ash/public/cpp/shelf_types.h b/ash/public/cpp/shelf_types.h
index 607419929edf2482ce9d7914b214e1af40b1fa17..fbed76c3bc4959e2f43e22f3ba8e8c2bcf125e28 100644
--- a/ash/public/cpp/shelf_types.h
+++ b/ash/public/cpp/shelf_types.h
@@ -5,6 +5,10 @@
 #ifndef ASH_PUBLIC_CPP_SHELF_TYPES_H_
 #define ASH_PUBLIC_CPP_SHELF_TYPES_H_
 
+#include <cstdint>
+
+#include "ash/public/cpp/ash_public_export.h"
+
 namespace ash {
 
 enum ShelfAlignment {
@@ -114,6 +118,9 @@ enum ShelfItemType {
   TYPE_UNDEFINED,
 };
 
+// Returns true if |type| is a valid ShelfItemType.
+ASH_PUBLIC_EXPORT bool IsValidShelfItemType(int64_t type);
+
 // Represents the status of applications in the shelf.
 enum ShelfItemStatus {
   // A closed shelf item, i.e. has no live instance.