DevTools: move non panel-specific CSS from layerPanel.css to timelinePanel.css

Source/devtools/front_end/layers/LayersPanel.js

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 19 matching lines @@
 
 /**
  * @constructor
  * @extends {WebInspector.PanelWithSidebarTree}
  * @implements {WebInspector.TargetManager.Observer}
  */
 WebInspector.LayersPanel = function()
 {
     WebInspector.PanelWithSidebarTree.call(this, "layers", 225);
     this.registerRequiredCSS("layersPanel.css");
+    this.registerRequiredCSS("timelinePanel.css");
     this._target = null;
 
     this.sidebarElement().classList.add("outline-disclosure");
     this.sidebarTree.element.classList.remove("sidebar-tree");
 
     WebInspector.targetManager.observeTargets(this);
     this._currentlySelectedLayer = null;
     this._currentlyHoveredLayer = null;
 
     this._layerTreeOutline = new WebInspector.LayerTreeOutline(this.sidebarTree);
@@ skipping 220 matching lines @@
 
 WebInspector.LayersPanelFactory.prototype = {
     /**
      * @return {!WebInspector.Panel}
      */
     createPanel: function()
     {
         return WebInspector.LayersPanel._instance();
     }
 }