Bug 1373229: P2. Disable DXVA HW decoder if ID3D10Multithread not supported. r=jya

MozReview-Commit-ID: OMFltNZaYe

--HG--
extra : rebase_source : 35b3dc14296c1630f9cebe000609b3e6e99e30f4

dom/media/platforms/wmf/DXVA2Manager.cpp

@@ -759,6 +759,11 @@ D3D11DXVA2Manager::InitInternal(layers::KnowsCompositor* aKnowsCompositor,
     }
   }
 
+  RefPtr<ID3D10Multithread> mt;
+  hr = mDevice->QueryInterface((ID3D10Multithread**)getter_AddRefs(mt));
+  NS_ENSURE_TRUE(SUCCEEDED(hr) && mt, hr);
+  mt->SetMultithreadProtected(TRUE);
+
   mDevice->GetImmediateContext(getter_AddRefs(mContext));
 
   hr = wmf::MFCreateDXGIDeviceManager(&mDeviceManagerToken,