Some other metrics we already have, Media.LoadType and Media.URLScheme:
https://uma.googleplex.com/p/chrome/histograms/?endDate=20180823&dayCount=28&histograms=Media.LoadType%2CMedia.URLScheme&fixupData=true&showMax=true&filters=platform%2Ceq%2CC%2Cisofficial%2Ceq%2CTrue&implicitFilters=isofficial

I think we should probably add "scheme" to the UKM Media.WebMediaPlayerState table. I'll write up a quick privacy entry for this and try to get that out next week.

We should also add the container information to UKM. I've started the privacy approval process at http://go/ukm-media

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b8139f73390d6638d8dc68169d4fd6af36f5ccd3

commit b8139f73390d6638d8dc68169d4fd6af36f5ccd3
Author: Dale Curtis <dalecurtis@chromium.org>
Date: Mon Aug 27 23:28:48 2018

Add detected codec and container UMA for local playback.

This will provide insight into the type of files which are being
used for local playback. Specifically the following UMA:

Media.DetectedAudioCodecHash.Local
Media.DetectedContainer.Local
Media.DetectedVideoCodecHash.Local

Local file detection is based on the URL scheme being file://,
filesystem://, content://, cid://, and chrome-extension://.

It's also possible to create a blob:// URL from a local file,
but per the fileapi team there's no way to know the blob:// URL
is from a local file. :| It's also not easy to add support since
it's unclear if that's a meaningful distinction. blobs may be
downloaded and backed by a local file implicitly so the line
between what has always been a local file and what was
downloaded is a bit blurry.

BUG= 877697 
TEST=Local playback shows up histograms.

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Ief1c56a6ee7782b0231f271ca4e64d364ee86ac4
Reviewed-on: https://chromium-review.googlesource.com/1188947
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Kenneth MacKay <kmackay@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586485}
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/chromecast/media/cma/test/frame_segmenter_for_test.cc
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/blink/webmediaplayer_impl.cc
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/ffmpeg/ffmpeg_common_unittest.cc
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/filters/demuxer_perftest.cc
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/filters/ffmpeg_demuxer.cc
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/filters/ffmpeg_demuxer.h
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/filters/ffmpeg_demuxer_unittest.cc
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/filters/ffmpeg_glue.cc
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/filters/ffmpeg_glue.h
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/media/test/pipeline_integration_test_base.cc
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/b8139f73390d6638d8dc68169d4fd6af36f5ccd3/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/023c3e643cf9af7efe3256dd98cd06cb6fedfd1b

commit 023c3e643cf9af7efe3256dd98cd06cb6fedfd1b
Author: Pavel Feldman <pfeldman@chromium.org>
Date: Tue Aug 28 17:59:47 2018

Fix non-ffmpeg-enabled compilation.

This is a follow up to r586485.

Bug:  877697 
Change-Id: Ie4cbcf90d3fd626ffe8d66832535ab8a0a9b227c
TBR: trivial
Reviewed-on: https://chromium-review.googlesource.com/1192698
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586779}
[modify] https://crrev.com/023c3e643cf9af7efe3256dd98cd06cb6fedfd1b/media/blink/webmediaplayer_impl.cc

I wasn't able to get this landed fast enough for M69, so bumping to M70 and will request merge after canary soak for two pending CLs.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d131da1edcf62917ef0fdc792fc2508c68758f08

commit d131da1edcf62917ef0fdc792fc2508c68758f08
Author: Dale Curtis <dalecurtis@chromium.org>
Date: Thu Aug 30 02:09:53 2018

Add URL scheme for src= media playback to UKM. Add Media.URLScheme2.

This adds the URL scheme to the Media.WebMediaPlayerState UKM table
as well as deprecates the Media.URLScheme metric in favor of the
Media.URLScheme2 metric which is only recorded for URL based
playbacks (i.e., it doesn't include MSE playbacks anymore).

Privacy approval complete at http://go/ukm-media

BUG= 877697 
TEST=updated tests.

Change-Id: I3719ebd09e1f11d831132039a34a4f955c5abc3d
Reviewed-on: https://chromium-review.googlesource.com/1189164
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587417}
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/blink/BUILD.gn
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/blink/watch_time_reporter_unittest.cc
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/blink/webmediaplayer_impl.cc
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/blink/webmediaplayer_impl_unittest.cc
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/blink/webmediaplayer_util.cc
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/blink/webmediaplayer_util.h
[add] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/blink/webmediaplayer_util_unittest.cc
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/mojo/interfaces/media_metrics_provider.mojom
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/mojo/services/media_metrics_provider.cc
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/mojo/services/media_metrics_provider.h
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/mojo/services/media_metrics_provider_unittest.cc
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/media/mojo/services/watch_time_recorder_unittest.cc
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/tools/metrics/histograms/histograms.xml
[modify] https://crrev.com/d131da1edcf62917ef0fdc792fc2508c68758f08/tools/metrics/ukm/ukm.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5bba03236922b2ed9a48264062d99793ddde0d9e

commit 5bba03236922b2ed9a48264062d99793ddde0d9e
Author: Dale Curtis <dalecurtis@chromium.org>
Date: Thu Aug 30 17:57:38 2018

Add container name for src= playbacks to UKM.

This adds the existing UMA container_names::MediaContainerName
enum value to UKM to help us understand media consumption for
both local and online cases better.

This only adds the metric for src= playbacks, it's much harder
to add for MSE since a MSE playback may have multiple formats
at a given time. The UMA we have for this is currently
sufficient.

Privacy approval complete at http://go/ukm-media

BUG= 877697 
TEST=updated tests.

Change-Id: I2baeb04010ab3c4708ca54b756229d92d69f6c51
Reviewed-on: https://chromium-review.googlesource.com/1192134
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587655}
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/chrome/browser/media/android/remote/record_cast_action.cc
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/chrome/browser/media/router/media_router_metrics.cc
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/base/container_names.h
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/base/ipc/media_param_traits_macros.h
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/blink/watch_time_reporter_unittest.cc
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/blink/webmediaplayer_impl.cc
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/blink/webmediaplayer_impl.h
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/mojo/interfaces/media_metrics_provider.mojom
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/mojo/interfaces/media_types.mojom
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/mojo/interfaces/media_types.typemap
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/mojo/services/media_metrics_provider.cc
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/mojo/services/media_metrics_provider.h
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/media/mojo/services/media_metrics_provider_unittest.cc
[modify] https://crrev.com/5bba03236922b2ed9a48264062d99793ddde0d9e/tools/metrics/ukm/ukm.xml

+MR70 so we can make decisions based on stable data for M72.

This bug requires manual review: We don't branch M70 until 2018-08-30.
Please contact the milestone owner if you have questions.
Owners: benmason@(Android), kariahda@(iOS), geohsu@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

lol nevermind, sorry I thought branch already happened on Tuesday. We've already missed stable cut for 69, so marking as fixed.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e37206fc7c2a08eef180f5e5fc7c708fea3dcd04

commit e37206fc7c2a08eef180f5e5fc7c708fea3dcd04
Author: Dale Curtis <dalecurtis@chromium.org>
Date: Tue Dec 04 01:43:38 2018

Fix Media.DetectedContainer.Local histogram.

The code path was only logging unsupported containers, so the results
were skewed by unrecognizable garbage.

BUG= 877697 

Change-Id: If3ec0019786cb388fafe599a7a773df15c3be08b
Reviewed-on: https://chromium-review.googlesource.com/c/1357624
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613382}
[modify] https://crrev.com/e37206fc7c2a08eef180f5e5fc7c708fea3dcd04/media/filters/ffmpeg_glue.cc