cc: refactor of MathUtil::AddToTracedValue

cc: refactor of MathUtil::AddToTracedValue

Pass the name to MathUtilAddToTracedValue
and decide the json value type internally.
so that we could add the value without knowing
the value type.

Committed: https://crrev.com/50f9c8e35e788b657d3b3cd825ece454a13ffc63
Cr-Commit-Position: refs/heads/master@{#312339}

[JungJik, 2015-01-19 05:54:57]

jungjik.lee@samsung.com changed reviewers:
+ danakj@chromium.org

[JungJik, 2015-01-19 05:54:57]

PTAL.

[vmpstr, 2015-01-20 17:42:58]

vmpstr@chromium.org changed reviewers:
+ vmpstr@chromium.org

[vmpstr, 2015-01-20 17:42:58]

lgtm, thanks!

[danakj, 2015-01-20 20:02:49]

LGTM

[JungJik, 2015-01-21 02:11:05]

The CQ bit was checked by jungjik.lee@samsung.com

[commit-bot: I haz the power, 2015-01-21 02:13:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/853393002/1

[commit-bot: I haz the power, 2015-01-21 14:06:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-21 14:08:49]

Patchset 1 (id:??) landed as
https://crrev.com/50f9c8e35e788b657d3b3cd825ece454a13ffc63
Cr-Commit-Position: refs/heads/master@{#312339}