Updates destroy in Vulkan's BindGroupLayout.

Bug: dawn:628
Change-Id: I728e5bc8c96df3bfe3f19c1841df20e28b79d76e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/70181
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Loko Kung <lokokung@google.com>

src/dawn_native/vulkan/BindGroupLayoutVk.cpp

@@ -152,7 +152,9 @@ namespace dawn_native { namespace vulkan {
           mBindGroupAllocator(MakeFrontendBindGroupAllocator<BindGroup>(4096)) {
     }
 
-    BindGroupLayout::~BindGroupLayout() {
+    BindGroupLayout::~BindGroupLayout() = default;
+
+    void BindGroupLayout::DestroyImpl() {
         Device* device = ToBackend(GetDevice());
 
         // DescriptorSetLayout aren't used by execution on the GPU and can be deleted at any time,

src/dawn_native/vulkan/BindGroupLayoutVk.h

@@ -65,6 +65,7 @@ namespace dawn_native { namespace vulkan {
       private:
         ~BindGroupLayout() override;
         MaybeError Initialize();
+        void DestroyImpl() override;
 
         // Dawn API
         void SetLabelImpl() override;