To test, open the DevTools (Ctrl+Shift+I) and reload the page.

Before running the tests please perform the following: Make sure the execution is not paused in the debugger.
Click the button and when the debugger breaks, set a breakpoint on the first line in the loop (as indicated by the comment), and click continue.
The debugger should stop at the beggining of the loop.
The above actions should be performed before each of the following tests.

TEST 1: Click 'continue'. Execution should continue without stopping on the loop breakpoint again.
TEST 2: Click 'Step into'. Debugger should step inside each function.
TEST 3: 'Step over' to the end of the loop (and 'while' statement) and step over again. Debugger should go to the beggining of the loop.