Ensure Dxgi duplicator works correctly in session 0

webrtc/modules/desktop_capture/win/dxgi_frame.cc

Index: webrtc/modules/desktop_capture/win/dxgi_frame.cc
diff --git a/webrtc/modules/desktop_capture/win/dxgi_frame.cc b/webrtc/modules/desktop_capture/win/dxgi_frame.cc
index 6e33b64527665a007fc413a7a6bae3fcf459fda5..79a9016b0fe605dd0c846aef1dd1721904c3012b 100644
--- a/webrtc/modules/desktop_capture/win/dxgi_frame.cc
+++ b/webrtc/modules/desktop_capture/win/dxgi_frame.cc
@@ -15,6 +15,7 @@
 #include <utility>
 
 #include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
 #include "webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.h"
 
@@ -46,6 +47,7 @@ bool DxgiFrame::Prepare(DesktopSize size, DesktopCapturer::SourceId source_id) {
       frame.reset(new BasicDesktopFrame(size));
     }
     if (!frame) {
+      LOG(LS_WARNING) << "DxgiFrame cannot create a new DesktopFrame.";
       return false;
     }
     // DirectX capturer won't paint each pixel in the frame due to its one