This test runs and profiles a simple looped computation.
    
    
    TEST
    
      - load file in the browser;
      
- open DevTools with console (Ctrl+Shift+I on Win/Linux, Command+Option+I on Mac);
      
- go to 'Profiles' page;
      
- observe that 'Profile 1' item has appeared under 'CPU profiles' section;
      
- check for presence of 'eternal_fib' entry in the profile view.