Activity Completion Report - Activity names get truncated in all browsers

In relation to MDL-47792.

When using Firefox or Chrome (IE Untested) in Windows and Safari, Chrome or Firefox in OS X, the Activity titles in the Activity Compeltion report is not showing fully.

The screenshot attached is using the Clean theme.

To reproduce:
1. Ensure completion tracking is turned on for the site and in the course
2. Add a couple of activities (configured for completion tracking) to the course content
3. Configure course completion to be dependent on at least one of the resources.
4. Ensure that at least one student is enrolled on the course
5. Access Course Administration > Reports > Activity Completion