Remove deprecated comments

webrtc/modules/desktop_capture/win/dxgi_output_duplicator.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 14 matching lines @@
 #include "webrtc/modules/desktop_capture/desktop_region.h"
 #include "webrtc/modules/desktop_capture/desktop_frame_rotation.h"
 #include "webrtc/modules/desktop_capture/shared_desktop_frame.h"
 #include "webrtc/modules/desktop_capture/win/d3d_device.h"
 #include "webrtc/modules/desktop_capture/win/dxgi_texture.h"
 
 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 {
     // The updated region DxgiOutputDuplicator::DetectUpdatedRegion() output
     // during last Duplicate() function call. It's a DesktopRegion translated by
     // offset of each DxgiOutputDuplicator instance.
     DesktopRegion updated_region;
   };
 
   // Creates an instance of DxgiOutputDuplicator from a D3dDevice and one of its
@@ skipping 79 matching lines @@
   // The last full frame of this output and its offset. If on AcquireNextFrame()
   // failed because of timeout, i.e. no update, we can copy content from
   // |last_frame_|.
   std::unique_ptr<SharedDesktopFrame> last_frame_;
   DesktopVector last_frame_offset_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_WIN_DXGI_OUTPUT_DUPLICATOR_H_