Validate incoming window properties.

ui/wm/core/shadow_types.cc

Index: ui/wm/core/shadow_types.cc
diff --git a/ui/wm/core/shadow_types.cc b/ui/wm/core/shadow_types.cc
index bf08bbec57e5b72081f292049f2ed898906fac4c..54c5b8c32a323eaa7a136377a97a98da91274dfd 100644
--- a/ui/wm/core/shadow_types.cc
+++ b/ui/wm/core/shadow_types.cc
@@ -4,12 +4,25 @@
 
 #include "ui/wm/core/shadow_types.h"
 
+#include "base/callback.h"
 #include "ui/base/class_property.h"
 
 DECLARE_EXPORTED_UI_CLASS_PROPERTY_TYPE(WM_EXPORT, ::wm::ShadowElevation);
 
 namespace wm {
 
+namespace {
+
+bool DoValidateShadowElevation(int32_t i) {
+  return i == int32_t(ShadowElevation::DEFAULT) ||
+         i == int32_t(ShadowElevation::NONE) ||
+         i == int32_t(ShadowElevation::SMALL) ||
+         i == int32_t(ShadowElevation::MEDIUM) ||
+         i == int32_t(ShadowElevation::LARGE);
+}
+
+}  // namespace
+
 DEFINE_UI_CLASS_PROPERTY_KEY(ShadowElevation,
                              kShadowElevationKey,
                              ShadowElevation::DEFAULT);
@@ -18,4 +31,8 @@ void SetShadowElevation(aura::Window* window, ShadowElevation elevation) {
   window->SetProperty(kShadowElevationKey, elevation);
 }
 
+base::RepeatingCallback<bool(int32_t)> ValidateShadowElevation() {
+  return base::Bind(&DoValidateShadowElevation);
+}
+
 }  // namespace wm