The Tor Browser / file revision

 function run_test() {

     let p = Cc["@mozilla.org/tools/profiler;1"];

     // Just skip the test if the profiler component isn't present.

     if (!p)

 	return;

     p = p.getService(Ci.nsIProfiler);

     if (!p)

 	return;

     do_check_true(!p.IsActive());

     // The function is entered with the profiler disabled.

     (function (){

 	p.StartProfiler(100, 10, ["js"], 1);

 	let n = 10000;

 	while (--n); // OSR happens here with the profiler enabled.

 	// An assertion will fail when this function returns, if the

 	// SPS stack was misbalanced.

     })();

     p.StopProfiler();

 }