Remove deprecated comments

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 1f22643971f1dbec11f2e5b321e260c948441cb9..02a781487e932a104919f86b2d4228b2f02c9022 100644
--- a/webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h
+++ b/webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h
@@ -32,7 +32,6 @@ namespace webrtc {
 
 // Duplicates the content on one IDXGIOutput, i.e. one monitor attached to one
 // video card. None of functions in this class is thread-safe.
-// TODO(zijiehe): Understand the meaning of rotation.
 class DxgiOutputDuplicator {
  public:
   struct Context {