Improve the AddElement and RemoveElement logic - don't add/remove if the element is/isn't in the collection
Improve the AddElement and RemoveElement logic - don't add/remove if the element is/isn't in the collection

VioletLife/CefSharp,rlmcneary2/CefSharp,jamespearce2006/CefSharp,jamespearce2006/CefSharp,jamespearce2006/CefSharp,jamespearce2006/CefSharp,wangzheng888520/CefSharp,VioletLife/CefSharp,Livit/CefSharp,jamespearce2006/CefSharp,VioletLife/CefSharp,wangzheng888520/CefSharp,rlmcneary2/CefSharp,dga711/CefSharp,VioletLife/CefSharp,Livit/CefSharp,rlmcneary2/CefSharp,dga711/CefSharp,Livit/CefSharp,rlmcneary2/CefSharp,dga711/CefSharp,Livit/CefSharp,wangzheng888520/CefSharp,wangzheng888520/CefSharp,dga711/CefSharp