[App banners] Add UMA metrics

[App banners] Add UMA metrics

DEPENDENT on 914813002

* Combines app_banner_metrics_ids.*, app_banner_utilities.*, and
  app_banner_metrics_id_list.* into the app_banner_metrics.* files.

* Gets rid of the Java-side metrics because we can control and react
  to them entirely from native-side calls now.

* Updates the histograms accordingly.

BUG=457416
TBR=thakis

Committed: https://crrev.com/aada8ca53d972120510a5c0de6484d029e004e93
Cr-Commit-Position: refs/heads/master@{#316936}

[gone, 2015-02-13 22:12:51]

dfalcantara@chromium.org changed reviewers:
+ yusufo@chromium.org

[gone, 2015-02-13 22:14:30]

benwells as FYI

[gone, 2015-02-13 22:15:50]

dfalcantara@chromium.org changed reviewers:
+ benwells@chromium.org

[gone, 2015-02-13 22:15:51]

Actually, reframing:

Ben for the changes to AppBannerSettingsHelper & AppBannerManager

Yusuf for the combination of the app_banner_metrics/app_banner_utilties files.

[benwells, 2015-02-15 23:54:43]

AppBannerManager and AppBannerSettingsHelper lgtm

[gone, 2015-02-18 02:21:00]

/me pokes Yusuf.

[Yusuf, 2015-02-18 22:49:38]

On 2015/02/18 at 02:21:00, dfalcantara wrote:
> /me pokes Yusuf.

lgtm

sorry for the delay.

[gone, 2015-02-18 23:00:27]

New patchsets have been uploaded after l-g-t-m from
benwells@chromium.org,yusufo@chromium.org

[gone, 2015-02-18 23:02:21]

dfalcantara@chromium.org changed reviewers:
+ cjhopman@chromium.org, isherman@chromium.org

[gone, 2015-02-18 23:02:22]

isherman@chromium.org: Please review changes in histograms.xml

cjhopman: Changes to BUILD.gn

[Ilya Sherman, 2015-02-19 00:28:23]

histograms.xml lgtm

[cjhopman, 2015-02-19 00:31:13]

lgtm

[gone, 2015-02-19 00:36:27]

TBRing thakis@ for OWNERS on BUILD.gn and chrome.gyp

[gone, 2015-02-19 00:36:33]

The CQ bit was checked by dfalcantara@chromium.org

[commit-bot: I haz the power, 2015-02-19 00:38:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/929533002/60001

[commit-bot: I haz the power, 2015-02-19 00:42:47]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-02-19 00:43:53]

Patchset 4 (id:??) landed as
https://crrev.com/aada8ca53d972120510a5c0de6484d029e004e93
Cr-Commit-Position: refs/heads/master@{#316936}