Fix leak of D3D12 fence share handle

The D3D12 fence share handle should be closed when the device is
deleted.

A future change will make it valid to call EndAccess after the device
is destroyed, thus the handle is closed in ~Device instead of
Device::DestroyImpl. It needs to live as long as ExternalImageDXGI
holds a reference onto the device.

Bug: chromium:1359106
Change-Id: Ib9c9aaa7fb0b5a3de035b512f8fc0316d4bd225e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/104540
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/dawn/native/d3d12/DeviceD3D12.cpp

@@ -193,6 +193,13 @@ MaybeError Device::Initialize(const DeviceDescriptor* descriptor) {
 
 Device::~Device() {
     Destroy();
+
+    // Close the handle here instead of in DestroyImpl. The handle is returned from
+    // ExternalImageDXGI, so it needs to live as long as the Device ref does, even if the device
+    // state is destroyed.
+    if (mFenceHandle != nullptr) {
+        ::CloseHandle(mFenceHandle);
+    }
 }
 
 ID3D12Device* Device::GetD3D12Device() const {

src/dawn/native/d3d12/ExternalImageDXGIImpl.cpp

@@ -111,7 +111,7 @@ WGPUTexture ExternalImageDXGIImpl::BeginAccess(
         }
     } else {
         d3d11on12Resource = mD3D11on12ResourceCache->GetOrCreateD3D11on12Resource(
-            mBackendDevice, mD3D12Resource.Get());
+            mBackendDevice.Get(), mD3D12Resource.Get());
         if (d3d11on12Resource == nullptr) {
             dawn::ErrorLog() << "Unable to create 11on12 resource for external image";
             return nullptr;

src/dawn/native/d3d12/ExternalImageDXGIImpl.h

@@ -58,7 +58,7 @@ class ExternalImageDXGIImpl : public LinkNode<ExternalImageDXGIImpl> {
     void EndAccess(WGPUTexture texture, ExternalImageDXGIFenceDescriptor* signalFence);
 
   private:
-    Device* mBackendDevice = nullptr;
+    Ref<Device> mBackendDevice;
     Microsoft::WRL::ComPtr<ID3D12Resource> mD3D12Resource;
     const bool mUseFenceSynchronization;