Third and hopefully last of thrre CLs to issue a warning when an older...

Third and hopefully last of thrre CLs to issue a warning when an older
version of the benchmark suite is run. This last change updates
bleeding_edge. 

Committed: http://code.google.com/p/v8/source/detail?r=2465

[Lasse Reichstein, 2009-07-14 14:30:46]

LGTM, with suggestions.

http://codereview.chromium.org/155496/diff/1/2
File benchmarks/run.html (right):

http://codereview.chromium.org/155496/diff/1/2#newcode58
Line 58: function ShowWarningIfObsolete() {
It might not be worth it to do this check if the banchmark is not received over
http (i.e., check location.protocol is "http:" or "https:"). Or even if it is
read from a location that isn't standard.
I.e., something like:
 if (!/^https?:.*\/v\d+\/run.html/i.test(location.href)) {
   return;
 }
You can even check that the digits in the href matches BenchmarkSuite.version,
or that it comes from the original v8.googlecode.com location.

http://codereview.chromium.org/155496/diff/1/2#newcode65
Line 65: if (window.XMLHttpRequest) {
I recommend using
 if (typeof XMLHttpRequest != "undefined") {
instead. It's dangerous to rely on boolean-conversion of host objects.
It's probably not important though (it reputedly works in IE, and that's the
most common cause of this kind of problems).

http://codereview.chromium.org/155496/diff/1/2#newcode66
Line 66: xmlhttp = new window.XMLHttpRequest();
You can drop the "window." in front.

http://codereview.chromium.org/155496/diff/1/2#newcode67
Line 67: } else if (window.ActiveXObject) {
Drop this test completely. If it fails, there is no case to fall through to, so
you might as well just try to create the object and fail if you can't.

http://codereview.chromium.org/155496/diff/1/2#newcode70
Line 70: xmlhttp.open('GET', next_version_url, true);
The third parameter makes the request asynchroneous. That means that the file
might be received while the benchmarks are being run, and might affect the
results.
It would be better to make it synchroneous, so it is done before the benchmarks
starts running.