The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/73d67f05926a02f23f5fbc1dd450d960cc2f96c6

commit 73d67f05926a02f23f5fbc1dd450d960cc2f96c6
Author: Tarun Bansal <tbansal@chromium.org>
Date: Wed Jan 17 05:56:25 2018

Experiment with lowering the priority of the resources in subframe

Experiment with dropping the priority of the resources in subrames
if the observed network quality is slower than the quality
specified in the experiment parameters. The experiment is
disabled by default.

Bug:  800035 
Change-Id: Ic1552545d8bfcfb0ccb60158c77ea71322780f46
Reviewed-on: https://chromium-review.googlesource.com/846287
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#529641}
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/chrome/browser/chrome_content_browser_client.cc
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/content/public/common/common_param_traits_macros.h
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/content/public/common/content_features.cc
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/content/public/common/content_features.h
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/content/public/common/web_preferences.cc
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/content/public/common/web_preferences.h
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/content/renderer/render_view_impl.cc
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/testing/variations/fieldtrial_testing_config.json
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/core/exported/WebSettingsImpl.cpp
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/core/exported/WebSettingsImpl.h
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/core/frame/Settings.h
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/core/frame/Settings.json5
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/core/loader/FrameFetchContext.h
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/platform/loader/fetch/FetchContext.h
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
[modify] https://crrev.com/73d67f05926a02f23f5fbc1dd450d960cc2f96c6/third_party/WebKit/public/web/WebSettings.h

Design doc (sorry, internal only): http://shortn/_OmZ9fpNUEK

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/98260cd1fa08fc8d49772c8ef5d414fd704a7550

commit 98260cd1fa08fc8d49772c8ef5d414fd704a7550
Author: Tarun Bansal <tbansal@chromium.org>
Date: Sat Feb 17 07:52:23 2018

Lower the priority of iframes in the browser

Previous CL did for frames and requests that start from Blink.
This CL additionally does it for frames or requests that
start in the browser.

Bug:  800035 
Change-Id: Id31dafa267a54971aa175077b017f5ee26d20d44
Reviewed-on: https://chromium-review.googlesource.com/922886
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537539}
[modify] https://crrev.com/98260cd1fa08fc8d49772c8ef5d414fd704a7550/content/browser/loader/navigation_url_loader_network_service.cc
[modify] https://crrev.com/98260cd1fa08fc8d49772c8ef5d414fd704a7550/content/browser/loader/navigation_url_loader_network_service_unittest.cc
[modify] https://crrev.com/98260cd1fa08fc8d49772c8ef5d414fd704a7550/content/browser/loader/resource_dispatcher_host_impl.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/98d574f33d72245a9ad4acd81683ec1a5f37fa0e

commit 98d574f33d72245a9ad4acd81683ec1a5f37fa0e
Author: Tarun Bansal <tbansal@chromium.org>
Date: Wed Feb 21 01:32:28 2018

Use different priorities for resources in iframes

Currently, when LowPriorityIframes experiment is enabled,
the priorities of all resources in iframes is lowered down
to kLowest.

This CL modifies the lowered priority to either kLow
or kLowest depending on the original priority of the resource.

Bug:  800035 
Change-Id: Iedab58980e9d2ebe6e395c30837dc235bc1c43a4
Reviewed-on: https://chromium-review.googlesource.com/927701
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537980}
[modify] https://crrev.com/98d574f33d72245a9ad4acd81683ec1a5f37fa0e/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
[modify] https://crrev.com/98d574f33d72245a9ad4acd81683ec1a5f37fa0e/third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/29e48dd0e04f6adc315465cdcc6af7ba6df4bd91

commit 29e48dd0e04f6adc315465cdcc6af7ba6df4bd91
Author: Tarun Bansal <tbansal@chromium.org>
Date: Mon Mar 05 22:10:11 2018

Add LowPriorityIframes.* histograms to histograms.xml

The two histograms were added to the WebKit code earlier, but
that CL did not add them to histograms.xml.
This CL adds the histogram description to the xml file.

Bug:  800035 
Change-Id: Ie42f4ccbdb35ea69324a8856af369f74db60fb60
Reviewed-on: https://chromium-review.googlesource.com/944247
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540955}
[modify] https://crrev.com/29e48dd0e04f6adc315465cdcc6af7ba6df4bd91/third_party/WebKit/public/platform/WebURLRequest.h
[modify] https://crrev.com/29e48dd0e04f6adc315465cdcc6af7ba6df4bd91/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/29e48dd0e04f6adc315465cdcc6af7ba6df4bd91/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/771ca695d3b7c537e7434c3b9d072f85edc8cd93

commit 771ca695d3b7c537e7434c3b9d072f85edc8cd93
Author: Tarun Bansal <tbansal@chromium.org>
Date: Mon Mar 19 19:50:19 2018

Rename LowPriorityIframes to LowPriorityIframes2 to avoid confusion

LowPriorityIframes2 is the name used in the server field trial
configs. This CL updates the name in the fieldtrial_testing_config
to be consistent with the server configs.

Bug:  800035 
Change-Id: I85a681e181be4b0a0bd8718f2671ff9ba062073b
Reviewed-on: https://chromium-review.googlesource.com/969115
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544132}
[modify] https://crrev.com/771ca695d3b7c537e7434c3b9d072f85edc8cd93/testing/variations/fieldtrial_testing_config.json

Tarun, is this complete now? If not, please make entry with the remaining work needed.

The experiment is still running. I need to do the data analysis.

Refreshed during triage.

tbansal, what work is left on this?

The experiment is running for 25% stable population. I need to do the data analysis.

Any updates?

I think we do not want to enable this until we have a better signals around network congestion. In the current format, it might slow down requests if we incorrectly detect network is congested (e.g., due to long polling XHRs).


Lets revisit this once we have better signals around detecting the network congestion.