public void ClearBrowserCache()
{
var historyManager = Xpcom.GetService<nsIBrowserHistory>(Contracts.NavHistoryService);
historyManager = Xpcom.QueryInterface<nsIBrowserHistory>(historyManager);
historyManager.RemoveAllPages();
ImageCache.ClearCache(true);
ImageCache.ClearCache(false);
CacheService.Clear(new CacheStoragePolicy());
}