Make BaselineOptimizer virtual test suite aware.

Make BaselineOptimizer virtual test suite aware.

With this patch, we'll optimize the virtual subtree, then see if we can
remove the virtual root baseline and then optimize the non-virtual subtree.

The new code and tests are kind of messy, but I didn't see a cleaner way to
do it. A lot of the mess comes from the fact the the virtual/* is both
in the directory name and in the baseline name.

BUG=237701
R=abarth@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=153716

[abarth-chromium, 2013-07-08 20:59:32]

LGTM

This change looked complicated at first, but after your explanation on the
whiteboard, it made a lot more sense.  I've noted below one place where you
might want to add some of that whiteboard information in a comment.  There might
be other places where it would be worthwhile.

I'd also recommend adding a link to
https://docs.google.com/a/chromium.org/drawings/d/1eGdsIKzJ2dxDDBbUaIABrN4aML...
in a comment somewhere too.  :)

https://codereview.chromium.org/18603012/diff/1/Tools/Scripts/webkitpy/common...
File Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py (right):

https://codereview.chromium.org/18603012/diff/1/Tools/Scripts/webkitpy/common...
Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py:85:
baseline_name_without_virtual = baseline_name
Can you add a comment with the example you wrote on the whiteboard?  This code
makes sense to me now because I can refer to the whiteboard, but I worry I'll
forget when I look at it next.

https://codereview.chromium.org/18603012/diff/1/Tools/Scripts/webkitpy/common...
Tools/Scripts/webkitpy/common/checkout/baselineoptimizer.py:236: def
_optimize_helper(self, baseline_name):
Is there a better name we can use here?  Perhaps _optimize_baseline(self,
baseline_name) ?

[ojan, 2013-07-08 22:57:50]

Committed patchset #1 manually as r153716 (presubmit successful).