[1110/125428.096505:ERROR:devtools_http_handler.cc(365)] GetMimeType d
+oesn't know mime type for: page/882884f3-27b2-42f3-81b1-a80cad81d727
+text/plain will be returned
I've never seen this error message from Chrome, but it seems that something really weird is happening with your setup and/or your machine.
Note that you can only access the devtools from one location, either from Perl or from within Chrome. It does not allow access from two things at once. If you open the devtools in Chrome after launching Perl, Perl will lose the access to the devtools.