美化边框滚动条插件OverlayScrollbars.js

OverlayScrollbars是一个JavaScript库，用于创建优雅,可自定义的滚动条元素。

callbacks: {
  onInitialized: callbackTemplate,                                 
  onInitializationWithdrawn: callbackTemplate,                     
  onDestroyed: callbackTemplate,                                   
  onScrollStart: callbackTemplate,                                 
  onScroll: callbackTemplate,                                      
  onScrollStop: callbackTemplate,                                  
  onOverflowChanged: callbackTemplate,                             
  onOverflowAmountChanged: callbackTemplate,                       
  onDirectionChanged: callbackTemplate,                            
  onContentSizeChanged: callbackTemplate,                          
  onHostSizeChanged: callbackTemplate,                             
  onUpdated: callbackTemplate                                      
}