Add DesktopFrame rotation functions

webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h

Index: webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h
diff --git a/webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h b/webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h
index 0d5b13479609b20e60222b4074bc60ba887b6fbb..b57569014fa84ac186a14e0c3955864a65283ae8 100644
--- a/webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h
+++ b/webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h
@@ -108,9 +108,6 @@ class DxgiOutputDuplicator {
   // Returns a DesktopRect in the coordinate of |texture_|->AsDesktopFrame().
   DesktopRect SourceRect(DesktopRect rect);
 
-  // Returns a DesktopRect in the coordinate of |offset|.
-  DesktopRect TargetRect(DesktopRect rect, DesktopVector offset);
-
   const D3dDevice device_;
   const Microsoft::WRL::ComPtr<IDXGIOutput1> output_;
   const DesktopRect desktop_rect_;