Add metric for tracking media playback utilization.

Add metric for tracking media playback utilization.

I.e., how many players completed preload but never saw playback. This
will be handy in terms of guiding efforts to reduce the number of these
types of "useless" players. I.e. maybe deferred offscreen loading, etc.

BUG=694855
TEST=manual

Review-Url: https://codereview.chromium.org/2709903002
Cr-Commit-Position: refs/heads/master@{#452135}
Committed: https://chromium.googlesource.com/chromium/src/+/c58ff8ebedea639ba58fb30a2e29faca9f8a0407

[DaleCurtis, 2017-02-22 01:13:11]

dalecurtis@chromium.org changed reviewers:
+ isherman@chromium.org, xhwang@chromium.org

[Ilya Sherman, 2017-02-22 01:27:42]

LGTM % comments

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:25835: +<histogram
name="Media.HasEverPlayed" units="Boolean">
nit: Please use a custom boolean with labels like "Played" and "Never played"
(changes needed in this file only, no C++ changes needed).

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:25838: +    Whether a given
WebMediaPlayer instance, after preload, started playback.
Please document when this is recorded -- when the instance is destroyed?  After
a timeout?  Something else?

[xhwang, 2017-02-22 01:32:20]

LGTM

Does it make sense to differentiate between auto-play players, and non-auto-play
players? I guess for auto-play players, "Played" rate will be close to one.

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:25838: +    Whether a given
WebMediaPlayer instance, after preload, started playback.
What's the frequency of this metric? Will this be reported for each media
element?

[DaleCurtis, 2017-02-22 01:33:16]

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:25835: +<histogram
name="Media.HasEverPlayed" units="Boolean">
On 2017/02/22 at 01:27:42, Ilya Sherman wrote:
> nit: Please use a custom boolean with labels like "Played" and "Never played"
(changes needed in this file only, no C++ changes needed).

Done.

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:25838: +    Whether a given
WebMediaPlayer instance, after preload, started playback.
On 2017/02/22 at 01:27:42, Ilya Sherman wrote:
> Please document when this is recorded -- when the instance is destroyed? 
After a timeout?  Something else?

Done (when WMPI is destroyed via ~WMPI or process exit).

[DaleCurtis, 2017-02-22 01:34:17]

For my purpose I don't think it matters to distinguish autoplay; that will count
in this case.

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/2709903002/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:25838: +    Whether a given
WebMediaPlayer instance, after preload, started playback.
On 2017/02/22 at 01:33:16, DaleCurtis wrote:
> On 2017/02/22 at 01:27:42, Ilya Sherman wrote:
> > Please document when this is recorded -- when the instance is destroyed? 
After a timeout?  Something else?
> 
> Done (when WMPI is destroyed via ~WMPI or process exit).

It will be recorded for every WMPI instance, which occurs whenever an
HTMLMediaElement instance has its src= set.

[DaleCurtis, 2017-02-22 01:34:45]

Said more clearly, autoplay counts as usage for this purpose.

[DaleCurtis, 2017-02-22 01:36:35]

The CQ bit was checked by dalecurtis@chromium.org

[DaleCurtis, 2017-02-22 01:36:35]

The patchset sent to the CQ was uploaded after l-g-t-m from xhwang@chromium.org,
isherman@chromium.org
Link to the patchset: https://codereview.chromium.org/2709903002/#ps20001
(title: "Use custom boolean for metric.")

[commit-bot: I haz the power, 2017-02-22 01:37:54]

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, 2017-02-22 09:36:38]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-02-22 09:36:40]

Try jobs failed on following builders:
  linux_chromium_asan_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[DaleCurtis, 2017-02-22 16:51:41]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2017-02-22 16:52:15]

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, 2017-02-22 18:20:50]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1487782301471970,
"parent_rev": "8d583449f10c29e8adf736099d0437ef03fb504d", "commit_rev":
"c58ff8ebedea639ba58fb30a2e29faca9f8a0407"}

[commit-bot: I haz the power, 2017-02-22 18:21:33]

Description was changed from

==========
Add metric for tracking media playback utilization.

I.e., how many players completed preload but never saw playback. This
will be handy in terms of guiding efforts to reduce the number of these
types of "useless" players. I.e. maybe deferred offscreen loading, etc.

BUG=694855
TEST=manual
==========

to

==========
Add metric for tracking media playback utilization.

I.e., how many players completed preload but never saw playback. This
will be handy in terms of guiding efforts to reduce the number of these
types of "useless" players. I.e. maybe deferred offscreen loading, etc.

BUG=694855
TEST=manual

Review-Url: https://codereview.chromium.org/2709903002
Cr-Commit-Position: refs/heads/master@{#452135}
Committed:
https://chromium.googlesource.com/chromium/src/+/c58ff8ebedea639ba58fb30a2e29...
==========

[commit-bot: I haz the power, 2017-02-22 18:21:36]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/c58ff8ebedea639ba58fb30a2e29...