Add PendingEvents UMA to ConnectionEventTracker shutdown.

Add PendingEvents UMA to ConnectionEventTracker shutdown.

Currently, the ConnectionEventTracker keeps a buffer in memory of events
which still need to be sent to GCM. If there is a shutdown, those events
are discarded without reaching GCM. This CL adds a metric to track the
event count at shutdown to give an estimate of how many events are being
lost and whether a persistence layer needs to be added.

BUG=662983
Review-Url: https://codereview.chromium.org/2594373002
Cr-Commit-Position: refs/heads/master@{#443208}
Committed: https://chromium.googlesource.com/chromium/src/+/a21137ae0b53e26cde0941be1bf86f7bf4986b5d

[harkness, 2016-12-22 10:50:14]

harkness@chromium.org changed reviewers:
+ peter@chromium.org

[Peter Beverloo, 2016-12-22 11:24:36]

lgtm % comments

https://codereview.chromium.org/2594373002/diff/1/google_apis/gcm/engine/conn...
File google_apis/gcm/engine/connection_event_tracker.cc (right):

https://codereview.chromium.org/2594373002/diff/1/google_apis/gcm/engine/conn...
google_apis/gcm/engine/connection_event_tracker.cc:24:
UMA_HISTOGRAM_ENUMERATION("GCM.PendingEvents", completed_events_.size(),
Let's call this PendingConnectionEventsAtShutdown?

https://codereview.chromium.org/2594373002/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/2594373002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:19105: +<histogram
name="GCM.PendingEvents">
units="events"

https://codereview.chromium.org/2594373002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:19108: +    Number of connection events
which have not been sent to the GCM. This is
nit: s/the//

[harkness, 2016-12-23 13:52:56]

https://codereview.chromium.org/2594373002/diff/1/google_apis/gcm/engine/conn...
File google_apis/gcm/engine/connection_event_tracker.cc (right):

https://codereview.chromium.org/2594373002/diff/1/google_apis/gcm/engine/conn...
google_apis/gcm/engine/connection_event_tracker.cc:24:
UMA_HISTOGRAM_ENUMERATION("GCM.PendingEvents", completed_events_.size(),
On 2016/12/22 11:24:36, Peter Beverloo (OOO - Jan 3rd) wrote:
> Let's call this PendingConnectionEventsAtShutdown?

Done.

https://codereview.chromium.org/2594373002/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/2594373002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:19105: +<histogram
name="GCM.PendingEvents">
On 2016/12/22 11:24:36, Peter Beverloo (OOO - Jan 3rd) wrote:
> units="events"

Done.

https://codereview.chromium.org/2594373002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:19108: +    Number of connection events
which have not been sent to the GCM. This is
On 2016/12/22 11:24:36, Peter Beverloo (OOO - Jan 3rd) wrote:
> nit: s/the//

Done.

[harkness, 2016-12-23 13:55:10]

harkness@chromium.org changed reviewers:
+ haraken@chromium.org, zea@chromium.org

[harkness, 2016-12-23 13:55:10]

zea@chromium.org: Please review changes in gcm_driver.

haraken@chromium.org: Please review changes in histograms.

[haraken, 2016-12-23 14:13:46]

haraken@chromium.org changed reviewers:
+ isherman@chromium.org

[haraken, 2016-12-23 14:13:46]

+isherman for histograms

(I can review UseCounter changes only.)

[Ilya Sherman, 2016-12-24 01:22:26]

Metrics LGTM

[Nicolas Zea, 2017-01-11 22:06:03]

lgtm

[harkness, 2017-01-12 09:56:36]

The CQ bit was checked by harkness@chromium.org

[harkness, 2017-01-12 09:56:36]

The patchset sent to the CQ was uploaded after l-g-t-m from peter@chromium.org
Link to the patchset: https://codereview.chromium.org/2594373002/#ps20001
(title: "Renamed histogram and nits")

[commit-bot: I haz the power, 2017-01-12 09:56:52]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-12 11:35:20]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1484214996224130,
"parent_rev": "05fd6942317394a4dbc4aae9fddc5511bb1fe00b", "commit_rev":
"a21137ae0b53e26cde0941be1bf86f7bf4986b5d"}

[commit-bot: I haz the power, 2017-01-12 11:35:52]

Description was changed from

==========
Add PendingEvents UMA to ConnectionEventTracker shutdown.

Currently, the ConnectionEventTracker keeps a buffer in memory of events
which still need to be sent to GCM. If there is a shutdown, those events
are discarded without reaching GCM. This CL adds a metric to track the
event count at shutdown to give an estimate of how many events are being
lost and whether a persistence layer needs to be added.

BUG=662983
==========

to

==========
Add PendingEvents UMA to ConnectionEventTracker shutdown.

Currently, the ConnectionEventTracker keeps a buffer in memory of events
which still need to be sent to GCM. If there is a shutdown, those events
are discarded without reaching GCM. This CL adds a metric to track the
event count at shutdown to give an estimate of how many events are being
lost and whether a persistence layer needs to be added.

BUG=662983

Review-Url: https://codereview.chromium.org/2594373002
Cr-Commit-Position: refs/heads/master@{#443208}
Committed:
https://chromium.googlesource.com/chromium/src/+/a21137ae0b53e26cde0941be1bf8...
==========

[commit-bot: I haz the power, 2017-01-12 11:35:53]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/a21137ae0b53e26cde0941be1bf8...