Samsung Galaxy S3 random reboot during clipboard use
When I read your question it sounded like a Chrome bug to me.

I looked around, and YES, it's a bug on Samsung's multi-entry clipboard feature, and it's been reported here. 

Here are two things you can do to fix this:
(1) If your phone is rooted, delete the contents of "/data/clipbord/*".
(2) OR, Do a factory reset.