text: /* See license.txt for terms of usage */
  
  "use strict";
  
  const { Trace, TraceError } = require("../core/trace.js").get(module.id);
  const { loadSheet, removeSheet } = require("sdk/stylesheet/utils");
  const { Class } = require("sdk/core/heritage");
  const { BaseOverlay } = require("../chrome/base-overlay.js");
  
  /**
   * @overlay This object represents an overlay that is responsible
   * for customizing the 'Timeline' panel.
   */
  const TimelineOverlay = Class(
  /** @lends TimelineOverlay */
  {
    extends: BaseOverlay,
  
    // Initialization
    initialize: function(options) {
      // xxxFlorent: is it useful just to trace? Should we remove this function?
      BaseOverlay.prototype.initialize.apply(this, arguments);
  
      Trace.sysout("timelineOverlay.initialize;", options);
    },
  
    onReady: function(options) {
      BaseOverlay.prototype.onReady.apply(this, arguments);
  
      Trace.sysout("timelineOverlay.onReady;", options);
    },
  
    destroy: function() {
      Trace.sysout("timelineOverlay.destroy;", arguments);
    },
  
    onApplyTheme: function(win, oldTheme) {
      loadSheet(win, "chrome://firebug/skin/timeline.css", "author");
      loadSheet(win, "chrome://firebug/skin/panel-content.css", "author");
    },
  
    onUnapplyTheme: function(win, newTheme) {
      removeSheet(win, "chrome://firebug/skin/timeline.css", "author");
      removeSheet(win, "chrome://firebug/skin/panel-content.css", "author");
    }
  });
  
  // Exports from this module
  exports.TimelineOverlay = TimelineOverlay;
  