Profiler: test profiles population on DevTools re-opening

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;
reload page in browser;
observe that after 5 seconds, 'Profile 2' item has appeared under 'CPU profiles' section;
take a couple of heap snapshots by pressing 'Take heap snapshot.' button (eye icon on the left of the status bar);
close DevTools window;
re-open DevTools window;
go to 'Profiles' page;
verify that CPU profiles 'Profile 1' and 'Profile 2', and heap profiles taken previously are restored back (Warning: it may take some time to re-process them).