Add headless Chromium installation to the browsers for Linux

playwright-driver/default.nix

@@ -137,6 +137,16 @@ EOF
         makeWrapper ${chromium}/bin/chromium $out/chromium-$CHROMIUM_REVISION/chrome-linux/chrome \
           --set SSL_CERT_FILE /etc/ssl/certs/ca-bundle.crt \
           --set FONTCONFIG_FILE ${fontconfig}
+
+        # We also need to install the headless shell version of Chromium
+        CHROMIUM_HEADLESS_SHELL_REVISION=$(jq -r '.browsers[] | select(.name == "chromium-headless-shell").revision' $BROWSERS_JSON)
+        mkdir -p $out/chromium-headless-shell-$CHROMIUM_HEADLESS_SHELL_REVISION/chrome-linux
+
+        # See here for the Chrome options:
+        # https://github.com/NixOS/nixpkgs/issues/136207#issuecomment-908637738
+        makeWrapper ${chromium}/bin/chromium $out/chromium_headless_shell-$CHROMIUM_REVISION/chrome-linux/headless_shell \
+          --set SSL_CERT_FILE /etc/ssl/certs/ca-bundle.crt \
+          --set FONTCONFIG_FILE ${fontconfig}
       '' + ''
         FFMPEG_REVISION=$(jq -r '.browsers[] | select(.name == "ffmpeg").revision' $BROWSERS_JSON)
         mkdir -p $out/ffmpeg-$FFMPEG_REVISION