Bug 1292498 - Don't support D3D11 feature level 9_3 since it doesn't work with any of our use cases. r=Bas

gfx/thebes/DeviceManagerD3D11.cpp

@@ -55,7 +55,6 @@ DeviceManagerD3D11::DeviceManagerD3D11()
   mFeatureLevels.AppendElement(D3D_FEATURE_LEVEL_11_0);
   mFeatureLevels.AppendElement(D3D_FEATURE_LEVEL_10_1);
   mFeatureLevels.AppendElement(D3D_FEATURE_LEVEL_10_0);
-  mFeatureLevels.AppendElement(D3D_FEATURE_LEVEL_9_3);
 }
 
 static inline bool