Untitled

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Hello World!</title>
    <style>
        #master {
            position: absolute;
            left: 0;
            width: 50%;
            top: 60px;
            bottom: 0;
            height: 400px;
            border: 10px red solid;
        }
    </style>
  </head>
  <body>
    <webview id="master" src="./master.html"></webview>
    <script>
      let master = document.getElementById('master');
      master.addEventListener('dom-ready', (...arg) => {
        master.getWebContents().debugger.attach('1.3');
        master.getWebContents().debugger.sendCommand('Emulation.setTouchEmulationEnabled', {
            enabled: true,
            maxTouchPoints: 1
        });
        master.getWebContents().debugger.sendCommand('Emulation.setEmitTouchEventsForMouse', {
            enabled: true,
            configuration: 'mobile'
        });
        master.getWebContents().openDevTools();
      });
    </script>
  </body>
</html>