scripts: Fix mem leak from vkResetDescriptorPool

Track which descriptor sets are allocated from each pool in the handle
wrapping code.  Clean up implicitly freed descriptor sets when a
descriptor pool is reset or destroyed.

Change-Id: Idb473562a7b5e571281de991e0fccc5ea92a9b57
diff --git a/scripts/layer_chassis_generator.py b/scripts/layer_chassis_generator.py
index 1e18937..5655675 100644
--- a/scripts/layer_chassis_generator.py
+++ b/scripts/layer_chassis_generator.py
@@ -221,6 +221,8 @@
         // Map of wrapped swapchain handles to arrays of wrapped swapchain image IDs
         // Each swapchain has an immutable list of wrapped swapchain image IDs -- always return these IDs if they exist
         std::unordered_map<VkSwapchainKHR, std::vector<VkImage>> swapchain_wrapped_image_handle_map;
+        // Map of wrapped descriptor pools to set of wrapped descriptor sets allocated from each pool
+        std::unordered_map<VkDescriptorPool, std::unordered_set<VkDescriptorSet>> pool_descriptor_sets_map;
 
 
         // Unwrap a handle.  Must hold lock.