This is the test for basic functionality of heap snapshot 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 'Take heap snapshot' button
        (eye icon on the left side of status bar);
    
    On the left pane under 'Heap snapshots' section, an item called
    'Snapshot 1' must appear, and a grid with snapshot 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 'Count' and
        'Size' columns to toggle between times and percents for
        this column only;
      
- expanding and collapsing tree nodes.