This small piece of logic is duplicated in DxgiDuplicatorController, DxgiAdapterDuplicator and desktop_configuration.mm. Meanwhile, the implementation in desktop_configuration.mm is not safe. So I think a function in DesktopRect to cover the requirement could be more efficient and safer. BUG=webrtc:7541 Review-Url: https://codereview.webrtc.org/2845213002 Cr-Commit-Position: refs/heads/master@{#18171}