This test runs a simple looped computation to test basic
    functionality of profile view grid.
    
    
    To use this test:
    
      - load file in the browser;
      
- open DevTools (Ctrl+Shift+I on Win/Linux, Command+Option+I on Mac);
      
- go to 'Profiles' page;
      
- press 'Start profiling' button
        (gray dot on the left side of status bar);
      
- wait for 5 seconds;
      
- press 'Stop profiling' button
        (red dot on the left side of status bar);
    
    On the left pane under 'CPU profiles' section, an item called
    'Profile 1' must appear, and a grid with profile data must
    appear on the right. Now test the following functionality in the grid:
    
      - change sorting order in each column by clicking on its header;
      
- resize each column;
      
- toggle between showing absolute times and percents
        (button with percent sign on the status bar);
      
- double-click on numbers in 'Self' and
        'Total' columns to toggle between times and percents for
        this column only;
      
- expanding and collapsing tree nodes;
      
- toggling between "Heavy" and "Tree" views.