old_contents: // Gets character limit and allows no more
  $(function() {
    // Creates the character count elements
    $(".js-char-count").wrap("<div class='char-count'></div>")
    $(".js-char-count").after("<div class='char-text'>Character count: <span class='current-count'>0</span></div>");
  
    // Includes charact limit if there is one
    $(".js-char-count").each(function(){
      var maxlength = $(this).attr('maxlength');
      if (maxlength) {
        $(this).closest(".char-count").find(".char-text").append("/<span class='total-count'>" +maxlength+ "</span>")
      }
    });
  
    // On keydown, gets character count
    $(".js-char-count").on('keyup', function () {
      content = $(this).val().replace(/(\r\n|\n|\r)/gm,"  ");
      $(this).closest(".char-count").find(".char-text .current-count").text(content.length);
  
      // If character count is over the limit then show error
      if (content.length > $(this).attr('maxlength')) {
        $(this).closest(".char-count").addClass("char-over");
      } else {
        $(this).closest(".char-count").removeClass("char-over");
      }
    });
  });
  
new_contents: // Gets character limit and allows no more
  $(function() {
    // Creates the character count elements
    $(".js-char-count").wrap("<div class='char-count'></div>")
    $(".js-char-count").after("<div class='char-text'>Character count: <span class='current-count'>0</span></div>");
  
    // Includes charact limit if there is one
    $(".js-char-count").each(function(){
      var maxlength = $(this).attr('maxlength');
      if (maxlength) {
        $(this).closest(".char-count").find(".char-text").append("/<span class='total-count'>" +maxlength+ "</span>")
      }
    });
  
    // On keydown, gets character count
    $(".js-char-count").on('keyup', function () {
      // Webkit counts a new line as a two characters
      // IE doesn't use maxlength
      var newline = "  ";
  
      if (navigator.userAgent.toLowerCase().indexOf('firefox') > -1) {
        // Firefox counts a new line as a singular character
        newline = " ";
      }
  
      content = $(this).val().replace(/(\r\n|\n|\r)/gm,"  ");
      $(this).closest(".char-count").find(".char-text .current-count").text(content.length);
  
      // If character count is over the limit then show error
      if (content.length > $(this).attr('maxlength')) {
        $(this).closest(".char-count").addClass("char-over");
      } else {
        $(this).closest(".char-count").removeClass("char-over");
      }
    });
  });
  
subject: Fix char count for Firefox