Nautilus progress bar is easily lead users to cancel the running task

Steps to reproduce

People often check the progress of tasks when they copying or deleting some large files using the nautilus progress bar. Usually, they would click a button to close the popped progress bar.

Reproducible in:

• Ubuntu 18.10 and libgtk 3.24.4.

Current behavior

The nautilus progress bar is very easy to lead users to click the cancel task button since there is only one button on the progress bar which is very like a closing window button.

Expected behavior

I suggest it add a confirm message box or change the cancel task button to other more accurate icons.

Additional information

This issue was firstly submitted in launchpad.