Description
        This test validates that the performance.clearMarks() method is working properly. This test creates the
           following marks to test this method:
            
           After creating each mark, performance.clearMarks() is called three times. First, it is provided with a name
           of "markUndefined", a non-existent mark, which shouldn't change the state of the Performance Timeline. Next,
           it is provided with a name of "mark2", after which, this mark should no longer be present in the Performance
           Timeline. Finally, performance.clearMarks() is called without any name provided. After this call, no marks
           should be present in the Performance Timeline. The state of the Performance Timeline is tested with the
           performance.getEntriesByType() and performance.getEntries() methods.