- From chromium source, find `gn.exe.sha1` file and get content of file. You can search at https://cs.chromium.org with `file:gn.exe.sha1` .

- The content is something like `c0d03f78af494365ff38c663297a20fe61da29ea`, 
  download file from url `https://storage.googleapis.com/chromium-gn/<content of file>`, like
  `https://storage.googleapis.com/chromium-gn/c0d03f78af494365ff38c663297a20fe61da29ea` and rename the downloaded file to `gn.exe`