Not a UI facing change => NA.
Should not impact A11Y => NA.

Dave, what's the earliest milestone we can aim for?
I'm assuming that we'll do a finch experiment to observe the benefit and any breakage.

Does the following plan look reasonable?
 1. Canary/Dev: 50/50
 2. Beta: 50/50
 3. Stable: 1%
 4. Stable: launch

Which metrics do we expect to see moving?
 - Event.Latency.BlockingTime.TouchStartDefaultAllowed ?
 - ?

Nevermind, the design doc had the info I was looking for:

"We expect to see a significant reduction in input latency due to this intervention, reflected in the input team’s end to end scroll latency metrics. In particular, we expect to see a drop of over 10% from the 99th percentile of Event.Latency.TouchToFirstScrollUpdateSwapBegin on Nexus 5."


"We also expect to see at least a 10% decrease in the percentage of events which are cancellable but not cancelled, which will be reflected in the Event.PassiveListeners metric."


Experiment: "50% of users in Canary/Dev" was mentioned.

Self assigning: I'll take care of the launch process.

I have a change ready to go for the canary/dev finch server configuration. It is just waiting the chromium side change to land so that I can put a proper min version number in the change.

Will let you know when I get it up for review.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/acc2fb2eaf19f06817b8ef90b64b195d032a662a

commit acc2fb2eaf19f06817b8ef90b64b195d032a662a
Author: dtapuska <dtapuska@chromium.org>
Date: Wed Jul 06 23:26:23 2016

Add option to force document level passive event listeners as a runtime feature.

This approach removes the value from the override setting and allows it
to be set as a runtime feature.

Since field trial variations aren't supported in the renderer and only
the browser process adding an additional runtime enabled feature seems
the easiest approach forward.

BUG= 625675 

Review-Url: https://codereview.chromium.org/2125683002
Cr-Commit-Position: refs/heads/master@{#403972}

[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/chrome/app/generated_resources.grd
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/chrome/browser/about_flags.cc
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/content/child/runtime_features.cc
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/content/public/common/content_features.cc
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/content/public/common/content_features.h
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/content/renderer/render_view_impl.cc
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/third_party/WebKit/Source/core/events/AddEventListenerOptionsDefaults.h
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/third_party/WebKit/Source/core/events/EventTarget.cpp
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/third_party/WebKit/Source/web/AssertMatchingEnums.cpp
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/third_party/WebKit/Source/web/WebRuntimeFeatures.cpp
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/third_party/WebKit/public/web/WebRuntimeFeatures.h
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/third_party/WebKit/public/web/WebSettings.h
[modify] https://crrev.com/acc2fb2eaf19f06817b8ef90b64b195d032a662a/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cba808f5a6b5b553da23c5612418ba6e8ce486a8

commit cba808f5a6b5b553da23c5612418ba6e8ce486a8
Author: dtapuska <dtapuska@chromium.org>
Date: Fri Jul 08 09:40:38 2016

Limit PassiveDocumentEventListeners to touch and make it experimental

Make sure we don't change the default for wheel listeners for document
elements so let the feature only work on touchstart and touchmove
listeners.

Enable it as experimental as well.

BUG= 625675 

Review-Url: https://codereview.chromium.org/2127163002
Cr-Commit-Position: refs/heads/master@{#404332}

[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/chrome/app/generated_resources.grd
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/content/child/runtime_features.cc
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/LayoutTests/fast/events/touch/compositor-touch-hit-rects-global.html
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/LayoutTests/fast/events/touch/resources/compositor-touch-hit-rects-iframe-doc.html
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/LayoutTests/fast/events/touch/resources/compositor-touch-hit-rects.js
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/LayoutTests/fast/events/touch/touch-event-cancelable.html
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/LayoutTests/fast/events/touch/touch-target-move-documents.html
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/LayoutTests/fullscreen/compositor-touch-hit-rects-fullscreen-video-controls.html
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/LayoutTests/inspector-protocol/input/emulateTouchFromMouseEvent.html
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/Source/core/events/EventTarget.cpp
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/Source/web/tests/FrameThrottlingTest.cpp
[modify] https://crrev.com/cba808f5a6b5b553da23c5612418ba6e8ce486a8/third_party/WebKit/Source/web/tests/data/touch-event-handler.html

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/19233086ad7e2363e7e1d14582dc6a5428816169

commit 19233086ad7e2363e7e1d14582dc6a5428816169
Author: dtapuska <dtapuska@chromium.org>
Date: Fri Jul 08 14:06:31 2016

Enable PassiveDocumentEventListeners on waterfall.

Enable passive document event listeners finch experimentl on waterfall.

BUG= 625675 
R=rkaplow@chromium.org

Review-Url: https://codereview.chromium.org/2119403002
Cr-Commit-Position: refs/heads/master@{#404351}

[modify] https://crrev.com/19233086ad7e2363e7e1d14582dc6a5428816169/testing/variations/fieldtrial_testing_config_android.json
[modify] https://crrev.com/19233086ad7e2363e7e1d14582dc6a5428816169/testing/variations/fieldtrial_testing_config_chromeos.json
[modify] https://crrev.com/19233086ad7e2363e7e1d14582dc6a5428816169/testing/variations/fieldtrial_testing_config_linux.json
[modify] https://crrev.com/19233086ad7e2363e7e1d14582dc6a5428816169/testing/variations/fieldtrial_testing_config_mac.json
[modify] https://crrev.com/19233086ad7e2363e7e1d14582dc6a5428816169/testing/variations/fieldtrial_testing_config_win.json

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/38e3bf349d518922038c1918bd76480bd2924fc4

commit 38e3bf349d518922038c1918bd76480bd2924fc4
Author: dtapuska <dtapuska@chromium.org>
Date: Wed Jul 13 19:53:39 2016

Revert of Enable PassiveDocumentEventListeners on waterfall. (patchset #2 id:20001 of https://codereview.chromium.org/2119403002/ )

Reason for revert:
Revert this for now. We are seeing cc:scheduler changes as a result of this and we need to understand them better and I'm not going to be in the office the next two days.

Original issue's description:
> Enable PassiveDocumentEventListeners on waterfall.
>
> Enable passive document event listeners finch experimentl on waterfall.
>
> BUG= 625675 
> R=rkaplow@chromium.org
>
> Committed: https://crrev.com/19233086ad7e2363e7e1d14582dc6a5428816169
> Cr-Commit-Position: refs/heads/master@{#404351}

TBR=rkaplow@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG= 625675 

Review-Url: https://codereview.chromium.org/2149673002
Cr-Commit-Position: refs/heads/master@{#405240}

[modify] https://crrev.com/38e3bf349d518922038c1918bd76480bd2924fc4/testing/variations/fieldtrial_testing_config_android.json
[modify] https://crrev.com/38e3bf349d518922038c1918bd76480bd2924fc4/testing/variations/fieldtrial_testing_config_chromeos.json
[modify] https://crrev.com/38e3bf349d518922038c1918bd76480bd2924fc4/testing/variations/fieldtrial_testing_config_linux.json
[modify] https://crrev.com/38e3bf349d518922038c1918bd76480bd2924fc4/testing/variations/fieldtrial_testing_config_mac.json
[modify] https://crrev.com/38e3bf349d518922038c1918bd76480bd2924fc4/testing/variations/fieldtrial_testing_config_win.json

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7a44b9eb2df493236df608d21681b563dbd74539

commit 7a44b9eb2df493236df608d21681b563dbd74539
Author: dtapuska <dtapuska@chromium.org>
Date: Mon Jul 18 15:47:21 2016

Add UMA metrics for root scroller intervention to track forcing passive breakage.

Calculate the number of event listener invocations that we didn't actually
end up allowing preventDefault to actually execute. The denominator
in this metric is the total number of invocations that we force passive
on.

BUG= 625675 

Review-Url: https://codereview.chromium.org/2137483003
Cr-Commit-Position: refs/heads/master@{#406002}

[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/core.gypi
[add] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/AddEventListenerOptionsResolved.cpp
[add] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/AddEventListenerOptionsResolved.h
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/Event.cpp
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/Event.h
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/EventListenerMap.cpp
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/EventListenerMap.h
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/EventTarget.cpp
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/EventTarget.h
[add] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/EventTargetTest.cpp
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/events/RegisteredEventListener.h
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/core/svg/SVGElement.cpp
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/modules/mediastream/MediaStream.cpp
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/modules/mediastream/MediaStream.h
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerGlobalScope.h
[modify] https://crrev.com/7a44b9eb2df493236df608d21681b563dbd74539/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/23914fdde83b0b7f763f34f00ff9fbba5d1a7611

commit 23914fdde83b0b7f763f34f00ff9fbba5d1a7611
Author: dtapuska <dtapuska@chromium.org>
Date: Wed Jul 27 16:49:51 2016

Turn off root scroller intervention on key_silk_cases page.

The http://s.codepen.io/befamous/fullpage/pFsqb?scroll pageset
seems to call preventDefault on every touchmove so to not cause
a regression with our root scroller intervention the page really
should articulate that it needs touch-action:none.

BUG= 625675 

Review-Url: https://codereview.chromium.org/2181413005
Cr-Commit-Position: refs/heads/master@{#408154}

[modify] https://crrev.com/23914fdde83b0b7f763f34f00ff9fbba5d1a7611/tools/perf/page_sets/key_silk_cases.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d8aa707343d3e3d067d919aa5d921da014944bc7

commit d8aa707343d3e3d067d919aa5d921da014944bc7
Author: dtapuska <dtapuska@chromium.org>
Date: Tue Aug 09 16:15:12 2016

Re-land Enable PassiveDocumentEventListeners on waterfall.

Enable passive document event listeners finch experimental on waterfall.

Originally reverted here: https://codereview.chromium.org/2149673002
Regression fixed via: https://codereview.chromium.org/2181413005

BUG= 625675 
R=rkaplow@chromium.org

Review-Url: https://codereview.chromium.org/2227823002
Cr-Commit-Position: refs/heads/master@{#410694}

[modify] https://crrev.com/d8aa707343d3e3d067d919aa5d921da014944bc7/testing/variations/fieldtrial_testing_config_android.json
[modify] https://crrev.com/d8aa707343d3e3d067d919aa5d921da014944bc7/testing/variations/fieldtrial_testing_config_chromeos.json
[modify] https://crrev.com/d8aa707343d3e3d067d919aa5d921da014944bc7/testing/variations/fieldtrial_testing_config_linux.json
[modify] https://crrev.com/d8aa707343d3e3d067d919aa5d921da014944bc7/testing/variations/fieldtrial_testing_config_mac.json
[modify] https://crrev.com/d8aa707343d3e3d067d919aa5d921da014944bc7/testing/variations/fieldtrial_testing_config_win.json

rbyers@ found this case that breaks with this intervention:
http://m.soundtransit.org/schedules?direction=outbound#40_100479

"Click on "view map", can't really pan the map vertically - scrolls instead.  I expect some breakage like this and it's still probably the right choice, but we need to keep an eye on it and publish good guidance."

(https://bugs.chromium.org/p/chromium/issues/detail?id=599609#c23)

For the benefits of the community, I made a public bug: https://bugs.chromium.org/p/chromium/issues/detail?id=639227

CL and general updates should be posted against it so that external folks can track progress.

Approved Intent to Intervene:

https://groups.google.com/a/chromium.org/d/msg/blink-dev/BW3qrkisqIs/v5Au-HVTAwAJ

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/25695dd787031a6def2a123277f405b709e2098a

commit 25695dd787031a6def2a123277f405b709e2098a
Author: dtapuska <dtapuska@chromium.org>
Date: Tue Nov 15 06:24:34 2016

Enable Root Document Level Passive Event Listeners

Switch flag to enabled by default. Approved intent to implement:

https://groups.google.com/a/chromium.org/d/msg/blink-dev/BW3qrkisqIs/v5Au-HVTAwAJ

BUG= 625675 

Review-Url: https://codereview.chromium.org/2501073002
Cr-Commit-Position: refs/heads/master@{#432130}

[modify] https://crrev.com/25695dd787031a6def2a123277f405b709e2098a/content/child/runtime_features.cc
[modify] https://crrev.com/25695dd787031a6def2a123277f405b709e2098a/content/public/common/content_features.cc
[modify] https://crrev.com/25695dd787031a6def2a123277f405b709e2098a/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in

WebKit bug: https://bugs.webkit.org/show_bug.cgi?id=175346