d3d11: Enable MultisampledSamplingTest

Bug: dawn:1705

Change-Id: I185b986b55f5c0b83f853bbeb059b0a9aa444483
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/137204
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Jie A Chen <jie.a.chen@intel.com>
diff --git a/src/dawn/tests/end2end/MultisampledSamplingTests.cpp b/src/dawn/tests/end2end/MultisampledSamplingTests.cpp
index d86a976..c08ecc0 100644
--- a/src/dawn/tests/end2end/MultisampledSamplingTests.cpp
+++ b/src/dawn/tests/end2end/MultisampledSamplingTests.cpp
@@ -259,6 +259,7 @@
 }
 
 DAWN_INSTANTIATE_TEST(MultisampledSamplingTest,
+                      D3D11Backend(),
                       D3D12Backend(),
                       MetalBackend(),
                       OpenGLBackend(),