Tests "step over" functionality in debugger.

Debugger was enabled.
Set timer for test function.
Script execution paused.
Call stack:
    0) d (debugger-step-over.html:14)
    1) testFunction (debugger-step-over.html:20)
Stepping over...
Script execution resumed.
Script execution paused.
Call stack:
    0) d (debugger-step-over.html:15)
    1) testFunction (debugger-step-over.html:20)
Stepping over...
Script execution resumed.
Script execution paused.
Call stack:
    0) d (debugger-step-over.html:16)
    1) testFunction (debugger-step-over.html:20)
Script execution resumed.
Debugger was disabled.