--- a/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
+++ b/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
@@ -19,17 +19,16 @@
 #include "MediaInfo.h"
 #include "MediaTelemetryConstants.h"
 #include "VPXDecoder.h"
 #include "VideoUtils.h"
 #include "WMFUtils.h"
 #include "gfx2DGlue.h"
 #include "gfxPrefs.h"
 #include "gfxWindowsPlatform.h"
-#include "mozilla/gfx/DeviceManagerDx.h"
 #include "mozilla/AbstractThread.h"
 #include "mozilla/ClearOnShutdown.h"
 #include "mozilla/Logging.h"
 #include "mozilla/SyncRunnable.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/WindowsVersion.h"
 #include "mozilla/layers/LayersTypes.h"
 #include "nsPrintfCString.h"
@@ -512,33 +511,21 @@ WMFVideoMFTManager::Init()
 
   return success;
 }
 
 bool
 WMFVideoMFTManager::InitInternal()
 {
   mUseHwAccel = false; // default value; changed if D3D setup succeeds.
-  RefPtr<ID3D11Device> device = gfx::DeviceManagerDx::Get()->GetContentDevice();
-  if (!device) {
-    device = gfx::DeviceManagerDx::Get()->GetCompositorDevice();
-  }
-  RefPtr<ID3D10Multithread> multi;
-  HRESULT hr =
-    device->QueryInterface((ID3D10Multithread**)getter_AddRefs(multi));
-  if (SUCCEEDED(hr)) {
-    multi->SetMultithreadProtected(TRUE);
-    mIMFUsable = true;
-  }
-
-  bool useDxva = mIMFUsable && InitializeDXVA();
+  bool useDxva = InitializeDXVA();
 
   RefPtr<MFTDecoder> decoder(new MFTDecoder());
 
-  hr = decoder->Create(GetMFTGUID());
+  HRESULT hr = decoder->Create(GetMFTGUID());
   NS_ENSURE_TRUE(SUCCEEDED(hr), false);
 
   RefPtr<IMFAttributes> attr(decoder->GetAttributes());
   UINT32 aware = 0;
   if (attr) {
     attr->GetUINT32(MF_SA_D3D_AWARE, &aware);
     attr->SetUINT32(CODECAPI_AVDecNumWorkerThreads,
       WMFDecoderModule::GetNumDecoderThreads());
@@ -847,17 +834,17 @@ WMFVideoMFTManager::CreateBasicVideoFram
 
   TimeUnit pts = GetSampleTime(aSample);
   NS_ENSURE_TRUE(pts.IsValid(), E_FAIL);
   TimeUnit duration = GetSampleDuration(aSample);
   NS_ENSURE_TRUE(duration.IsValid(), E_FAIL);
   nsIntRect pictureRegion = mVideoInfo.ScaledImageRect(videoWidth, videoHeight);
 
   LayersBackend backend = GetCompositorBackendType(mKnowsCompositor);
-  if (backend != LayersBackend::LAYERS_D3D11 || !mIMFUsable) {
+  if (backend != LayersBackend::LAYERS_D3D11) {
     RefPtr<VideoData> v =
       VideoData::CreateAndCopyData(mVideoInfo,
                                    mImageContainer,
                                    aStreamOffset,
                                    pts,
                                    duration,
                                    b,
                                    false,

--- a/dom/media/platforms/wmf/WMFVideoMFTManager.h
+++ b/dom/media/platforms/wmf/WMFVideoMFTManager.h
@@ -116,14 +116,13 @@ private:
 
   const GUID& GetMFTGUID();
   const GUID& GetMediaSubtypeGUID();
 
   uint32_t mNullOutputCount = 0;
   bool mGotValidOutputAfterNullOutput = false;
   bool mGotExcessiveNullOutput = false;
   bool mIsValid = true;
-  bool mIMFUsable = false;
 };
 
 } // namespace mozilla
 
 #endif // WMFVideoMFTManager_h_