Switch ChildProcess.* enum histograms from COUNTS to ENUMERATION.

Switch ChildProcess.* enum histograms from COUNTS to ENUMERATION.

These histograms shouldn't have been _COUNTS histograms in the first
place. _COUNTS histograms bucket the data in exponentially spaced buckets. This
causes, for example, PPAPI crashes to be bucketed together with (and as) GPU
crashes. To avoid messing up collected data and to ensure smooth transition,
renamed histograms.

BUG=chromium-os:21841
TEST=git try, looked at about:histograms

Change-Id: I137499992c60bdf6488561150f5b6642acc862b8


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=106993

[petkov, 2011-10-20 14:35:54]

I'll update the histogram-descriptions XML once this patch goes in.

jam: Please review, since you're in the OWNERS file.

jar: Please review, since this relates to UMA_ histograms.

cpu: Please review, since you touched this code and added some of the histograms
recently. More specifically, note that the histogram names need to change to
ensure smooth transition to the new histogram type on the server/dashboard side.

[jam, 2011-10-20 17:40:17]

lgtm

[cpu_(ooo_6.6-7.5), 2011-10-21 00:47:00]

lgtm

[jar (doing other things), 2011-10-21 01:50:35]

lgtm

[commit-bot: I haz the power, 2011-10-24 20:07:33]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/petkov@chromium.org/8356042/1

[commit-bot: I haz the power, 2011-10-24 20:09:50]

Try job failure for 8356042-1 on linux_clang for step "update".
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_clan...

Step "update" is always a major failure.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2011-10-24 20:55:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/petkov@chromium.org/8356042/1

[commit-bot: I haz the power, 2011-10-24 22:27:02]

Change committed as 106993