Expectations for 3 perf systems on morejs and startup....

Expectations for 3 perf systems on morejs and startup.

Set the perf expectations on linux, mac, and windows
perf systems for the morejs and warm startup tests.
The variance assumptions might require fine-tuning on
the master to get right.  We might be flaky to begin
with, or may want to turn off the variance reporting
altogether.

BUG=18597
TEST=build.chromium.org perf slaves stay green

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=26376

[chase, 2009-09-11 06:33:48]

I can land this during a period of inactivity and manually update the master's
perf expectations JSON file as a temp workaround until the upload patch lands
this weekend/early next week.  At that point, perf expectations will be updated
automatically.

The variances could get tricky to get right.  I suspect the master will need to
be tweaked so variances less than 30 or so use an absolute window instead of
generating a percentage of some already small number and relying on that.  Or we
may need to turn that code (the VAR_{IMPROVE, REGRESS} code) off entirely until
it's sorted out.  Things should be clearer on the ground.

[Nicolas Sylvain, 2009-09-11 17:02:06]

LGTM

[chase, 2009-09-16 19:29:53]

Updated based on latest results.