WebInspector.cssModel.addEventListener(WebInspector.CSSStyleModel.Events.StyleSheetAdded, styleSheetAdded, null);
WebInspector.cssModel.addEventListener(WebInspector.CSSStyleModel.Events.StyleSheetRemoved, styleSheetRemoved, null);
var headers = WebInspector.cssModel.styleSheetHeaders();
WebInspector.cssModel.addEventListener(WebInspector.CSSStyleModel.Events.StyleSheetAdded, styleSheetAdded, null);
WebInspector.cssModel.addEventListener(WebInspector.CSSStyleModel.Events.StyleSheetRemoved, styleSheetRemoved, null);
var headers = WebInspector.cssModel.styleSheetHeaders();