D3D12: Remove WrapSharedHandle

Removes WrapSharedHandle in favor of using
ExternalImageDXGI.

BUG=dawn:625

Change-Id: Ibd469600959aea344e7a59557d986fc673a79727
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/46020
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Bryan Bernhart <bryan.bernhart@intel.com>
diff --git a/src/include/dawn_native/D3D12Backend.h b/src/include/dawn_native/D3D12Backend.h
index e713623..b85a988 100644
--- a/src/include/dawn_native/D3D12Backend.h
+++ b/src/include/dawn_native/D3D12Backend.h
@@ -48,11 +48,8 @@
       public:
         ExternalImageDescriptorDXGISharedHandle();
 
+        // Note: SharedHandle must be a handle to a texture object.
         HANDLE sharedHandle;
-
-        // Warning: depreciated, replaced by ExternalImageAccessDescriptorDXGIKeyedMutex.
-        uint64_t acquireMutexKey;
-        bool isSwapChainTexture = false;
     };
 
     struct DAWN_NATIVE_EXPORT ExternalImageAccessDescriptorDXGIKeyedMutex
@@ -88,11 +85,6 @@
         uint32_t mSampleCount;
     };
 
-    // Warning: depreciated, replaced by ExternalImageDXGI::Create.
-    // Note: SharedHandle must be a handle to a texture object.
-    DAWN_NATIVE_EXPORT WGPUTexture
-    WrapSharedHandle(WGPUDevice device, const ExternalImageDescriptorDXGISharedHandle* descriptor);
-
     struct DAWN_NATIVE_EXPORT AdapterDiscoveryOptions : public AdapterDiscoveryOptionsBase {
         AdapterDiscoveryOptions(Microsoft::WRL::ComPtr<IDXGIAdapter> adapter);