I upgrade my mac os to the latest mac os 10.11.4, but i found some files and company works are missing. How can i get them...

I copied so many files on my macbook air desktop, after i ended my company work. I clean the desktop and delete the files...

Chromebook is just the generally referred to chrome os. So many manufacturers have chromebook. Such Samsung, Acer, HP, etc. So i think if the chromebook have normal hard disk, we could install data recovery software(.exe)on it. If the hypothesis can be set up, you can try do your data recovery , minitool or rstudio on it to try.

Trash bin is also a folder on mac system, you can only scan the system volume with mac data recovery software. And please remember don't use you mac again till the mac data recovery software get back your lost files.