Create the corresponding RenderTextureHost type and WR commands for DXGI texture type.
The DXGITextureHostD3D11 will use 1 or 2 image keys for non-nv12 and nv12 texture format.
The DXGIYCbCrTextureHostD3D11 is a special case. The WR uses ANGLE in windows platform,
but the ANGLE doesn't support A8 format directx texture directly. So, we use libyuv to
convert the DXGIYCbCrTextureHostD3D11 texture buffer into RGBA format buffer and use
WR::AddImage() for that image. This is a slow code path. We will refine this case later.
The whole RenderD3D11TextureHostOGL implementation is in the next patch.
MozReview-Commit-ID: F4mPCALj1OY
f488575a07