gistfile1.txt

//Paste this script on the console
//Config var, change this var at runtime to change the message
var autoMessage = prompt('Message to send');
//Support var
var isActive = false;
//Check every 200ms if the status of the textarea is changed
setInterval(function() {
  var isActiveNow = !document.querySelector('textarea.chatmsg').disabled;
  //If the textarea was previously disabled and now is enabled, means that we are meeting a new stranger
  //And obviously check if we have a message to send
  if ( !isActive && isActiveNow && autoMessage ) {
    //Write the message
    document.querySelector('textarea.chatmsg').value = autoMessage;
    //Send the message after 500ms
    setTimeout(function() {
      document.querySelector('button.sendbtn').click();
    },500);
  }
  //Update textarea status always
  isActive = isActiveNow;
},200);