Change bisect status message to print "positive" or "negative".

Change bisect status message to print "positive" or "negative".

This is a small CL in preparation for changing the wording in the output
to not refer to "confidence" (http://crbug.com/489351).

My intention is to:
 * Simplify the logic for the status part of the output.
 * Allow the dashboard to look for another string like "Status: Positive"
   or "Status: Negative" when deciding whether to CC, instead of looking
   at "Confidence: XX%".

BUG=489351
Committed: https://crrev.com/0bf5d57ab4527f4046ceab216db69cca181f17cc
Cr-Commit-Position: refs/heads/master@{#335295}

[qyearsley, 2015-06-18 15:55:24]

qyearsley@chromium.org changed reviewers:
+ prasadv@chromium.org

[qyearsley, 2015-06-18 15:55:25]

https://codereview.chromium.org/1181973009/diff/1/tools/auto_bisect/bisect_pr...
File tools/auto_bisect/bisect_printer.py (right):

https://codereview.chromium.org/1181973009/diff/1/tools/auto_bisect/bisect_pr...
tools/auto_bisect/bisect_printer.py:23: Test Metric: %(metric)s
Renaming metrics -> metric is minor change unrelated to the main purpose of this
CL; this is changed because in my understanding of the term, one "chart/trace"
name pair counts as one "metric".

[qyearsley, 2015-06-18 16:44:09]

On 2015/06/18 15:55:25, qyearsley wrote:
>
https://codereview.chromium.org/1181973009/diff/1/tools/auto_bisect/bisect_pr...
> File tools/auto_bisect/bisect_printer.py (right):
> 
>
https://codereview.chromium.org/1181973009/diff/1/tools/auto_bisect/bisect_pr...
> tools/auto_bisect/bisect_printer.py:23: Test Metric: %(metric)s
> Renaming metrics -> metric is minor change unrelated to the main purpose of
this
> CL; this is changed because in my understanding of the term, one "chart/trace"
> name pair counts as one "metric".

Note: After looking at the recipe version, I see that the recipe version uses
the "Status" section for a single-word status like: "Failed", "Aborted",
"Complete", "Successful", so maybe using the status section to say "Positive" or
"Negative" might not be the best thing.

What we really want to do is:
 * Indicate the overall status ("what kind of thing happened?") of the bisect
job in some simple way
 * Provide a string that the dashboard can look for when deciding whether to cc
authors besides "Confidence: XX%".

We could do both of these things with one status string, I think, but we should
decide on exactly what all of the statuses mean. Currently in the recipe version
they mean:
 * "Aborted": Full bisect not performed (but maybe the reference good/bad
results were obtained)
 * "Failed": ?
 * "Complete": Finished with warnings (and "confidence" may not be high)
 * "Successful": Finished without warnings (and "confidence" may not be high)

Proposal: Change this to only include:
 * "Aborted" (Full bisect not performed)
 * "Negative" (Finished, maybe with warnings, no culprit found with high
confidence)
 * "Positive" (Finished and one culprit was found with "high confidence")

Roberto, Prasad, what do you think?

[prasadv, 2015-06-19 17:08:37]

lgtm

[qyearsley, 2015-06-19 18:06:56]

The CQ bit was checked by qyearsley@chromium.org

[commit-bot: I haz the power, 2015-06-19 18:07:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1181973009/20001

[commit-bot: I haz the power, 2015-06-19 18:17:50]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-06-19 18:19:57]

Patchset 2 (id:??) landed as
https://crrev.com/0bf5d57ab4527f4046ceab216db69cca181f17cc
Cr-Commit-Position: refs/heads/master@{#335295}