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..710ab00f943ac1ece844f80c94a1aea5c6edbf2a 100644
--- a/ash/public/cpp/shelf_types.h
+++ b/ash/public/cpp/shelf_types.h
@@ -5,6 +5,11 @@
 #ifndef ASH_PUBLIC_CPP_SHELF_TYPES_H_
 #define ASH_PUBLIC_CPP_SHELF_TYPES_H_
 
+#include <cstdint>
+
+#include "ash/public/cpp/ash_public_export.h"
+#include "base/callback_forward.h"
+
 namespace ash {
 
 enum ShelfAlignment {
@@ -114,6 +119,11 @@ enum ShelfItemType {
   TYPE_UNDEFINED,
 };
 
+// Returns a callback which will return true if the value passed to it is a
+// valid ShelfItemType value.
+ASH_PUBLIC_EXPORT base::RepeatingCallback<bool(int32_t)>

[sky, 2017/02/23 21:02:25]

Why expose a callback here? I certainly get wanting a function like
IsValidShelfItemType(int32_t), but whether that's done using a callback seems
like something the consumers of this function should do.

[Elliot Glaysher, 2017/02/23 22:12:42]

Done.

+ValidateShelfItemType();
+
 // Represents the status of applications in the shelf.
 enum ShelfItemStatus {
   // A closed shelf item, i.e. has no live instance.