[App banners] Add server-controlled experiment to disable app banners

[App banners] Add server-controlled experiment to disable app banners

+ Dependent on cr/86724062

* Control the banner appearances via a kill-switch via an experiment.

* The app install alert flag in chrome://flags is now used to enable
  or disable app banners for Play Store apps.  Web app banners are
  only affected by the experiment.

BUG=457417
Committed: https://crrev.com/21061a10e616bd9ab99006fb72ce2851cc04641e
Cr-Commit-Position: refs/heads/master@{#317440}

[gone, 2015-02-19 23:39:27]

dfalcantara@chromium.org changed reviewers:
+ asvitkine@chromium.org, thakis@chromium.org

[gone, 2015-02-19 23:39:28]

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

thakis@chromium.org: Please review changes in everything else. Mainly deletions
of the the old flag.

[Nico, 2015-02-19 23:59:15]

https://codereview.chromium.org/941823002/diff/1/chrome/browser/about_flags.cc
File chrome/browser/about_flags.cc (left):

https://codereview.chromium.org/941823002/diff/1/chrome/browser/about_flags.c...
chrome/browser/about_flags.cc:1835: IDS_FLAGS_ENABLE_APP_INSTALL_ALERTS_NAME,
Can the IDS_s go too?

[gone, 2015-02-20 02:10:07]

https://chromiumcodereview.appspot.com/941823002/diff/1/chrome/browser/about_...
File chrome/browser/about_flags.cc (left):

https://chromiumcodereview.appspot.com/941823002/diff/1/chrome/browser/about_...
chrome/browser/about_flags.cc:1835: IDS_FLAGS_ENABLE_APP_INSTALL_ALERTS_NAME,
On 2015/02/19 23:59:15, Nico wrote:
> Can the IDS_s go too?

Good catch, removed.

[Nico, 2015-02-20 06:19:40]

lgtm

[Alexei Svitkine (slow), 2015-02-20 13:51:32]

lgtm % comments

nit: "Finch" is a codename, remove it from the CL description - you can just say
"experiment" or "server-controlled experiment"

https://chromiumcodereview.appspot.com/941823002/diff/40001/tools/metrics/his...
File tools/metrics/histograms/histograms.xml (left):

https://chromiumcodereview.appspot.com/941823002/diff/40001/tools/metrics/his...
tools/metrics/histograms/histograms.xml:51580: -  <int value="-1433087548"
label="enable-app-install-alerts"/>
Nit: Keep the old value here, so data from old versions can continue to be
decoded.

[gone, 2015-02-20 19:29:44]

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

[gone, 2015-02-20 22:32:19]

Well, this feature seems to be cursed in some way
(https://chromiumcodereview.appspot.com/229533002/).  The feature's been cleaved
into two for launch, with the kill switch applying to all app banners and the
config:flag being kept for play store banners (aiming for M43).

https://codereview.chromium.org/941823002/diff/40001/tools/metrics/histograms...
File tools/metrics/histograms/histograms.xml (left):

https://codereview.chromium.org/941823002/diff/40001/tools/metrics/histograms...
tools/metrics/histograms/histograms.xml:51580: -  <int value="-1433087548"
label="enable-app-install-alerts"/>
On 2015/02/20 13:51:31, Alexei Svitkine wrote:
> Nit: Keep the old value here, so data from old versions can continue to be
> decoded.

Done.

[gone, 2015-02-20 22:33:18]

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

[gone, 2015-02-20 22:33:18]

+tedchoc

But yeah, PTAL at the new changes.

[Ted C, 2015-02-20 22:58:30]

On 2015/02/20 22:33:18, dfalcantara wrote:
> +tedchoc
> 
> But yeah, PTAL at the new changes.

lgtm

[gone, 2015-02-20 23:03:19]

The CQ bit was checked by dfalcantara@chromium.org

[commit-bot: I haz the power, 2015-02-20 23:04:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/941823002/80001

[commit-bot: I haz the power, 2015-02-20 23:37:17]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-02-20 23:39:13]

Patchset 5 (id:??) landed as
https://crrev.com/21061a10e616bd9ab99006fb72ce2851cc04641e
Cr-Commit-Position: refs/heads/master@{#317440}