Several minor improvements of DirectX capturer

webrtc/modules/desktop_capture/win/dxgi_texture_staging.cc

Index: webrtc/modules/desktop_capture/win/dxgi_texture_staging.cc
diff --git a/webrtc/modules/desktop_capture/win/dxgi_texture_staging.cc b/webrtc/modules/desktop_capture/win/dxgi_texture_staging.cc
index 7478728143d0d8f93c274709e5d9207fc67073d4..9e82542ddf36821e80d3ded01d4553e9bb8cbdec 100644
--- a/webrtc/modules/desktop_capture/win/dxgi_texture_staging.cc
+++ b/webrtc/modules/desktop_capture/win/dxgi_texture_staging.cc
@@ -38,9 +38,13 @@ bool DxgiTextureStaging::InitializeStage(ID3D11Texture2D* texture) {
     return false;
   }
 
+  desc.ArraySize = 1;
   desc.BindFlags = 0;
   desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;
+  desc.MipLevels = 1;
   desc.MiscFlags = 0;
+  desc.SampleDesc.Count = 1;
+  desc.SampleDesc.Quality = 0;
   desc.Usage = D3D11_USAGE_STAGING;
   if (stage_) {
     AssertStageAndSurfaceAreSameObject();
@@ -58,7 +62,7 @@ bool DxgiTextureStaging::InitializeStage(ID3D11Texture2D* texture) {
     RTC_DCHECK(!surface_);
   }
 
-  _com_error error = _com_error(device_.d3d_device()->CreateTexture2D(
+  _com_error error(device_.d3d_device()->CreateTexture2D(
       &desc, nullptr, stage_.GetAddressOf()));
   if (error.Error() != S_OK || !stage_) {
     LOG(LS_ERROR) << "Failed to create a new ID3D11Texture2D as stage, error "