layers: Allow calling down chain with vkEnumerateDeviceExtensionProperties
diff --git a/layers/mem_tracker.cpp b/layers/mem_tracker.cpp
index f4f62c9..93b1d8e 100644
--- a/layers/mem_tracker.cpp
+++ b/layers/mem_tracker.cpp
@@ -1095,7 +1095,17 @@
         VkExtensionProperties*                      pProperties)
 {
     /* Mem tracker does not have any physical device extensions */
-    return util_GetExtensionProperties(0, NULL, pCount, pProperties);
+    if (pLayerName == NULL) {
+        layer_data *my_data = get_my_data_ptr(get_dispatch_key(physicalDevice), layer_data_map);
+        VkLayerInstanceDispatchTable *pInstanceTable = my_data->instance_dispatch_table;
+        return pInstanceTable->EnumerateDeviceExtensionProperties(
+                                                    physicalDevice,
+                                                    NULL,
+                                                    pCount,
+                                                    pProperties);
+    } else {
+        return util_GetExtensionProperties(0, NULL, pCount, pProperties);
+    }
 }
 
 VK_LAYER_EXPORT VkResult VKAPI vkEnumerateDeviceLayerProperties(