I'm taking a shot at adding a subpage so I can get to  issue 633455 . Michael, I'll probably assign back to you to add the existing battery and power source stuff since you have way more state there.

SGTM. We do need the subpage either way. However, keep in mind that we are not prioritizing new settings, so if we're not sure how long the power management settings will take or if the UX isn't final, probably best to use a flag.

keyboard.html/keyboard.js and the keyboard tests in device_page_tests.js are probably the simplest device sub-page to use as a starting point if you like. If your UI is dependent on the power source, you can use chrome://device-emulator in Debug builds to simulate those.

Not blocking MD Settings for Dev channel.

Are there any mocks for this?

I haven't seen any mocks.

OK. In the interest of launching on on CrOS I'll just do the minimum necessary to support Type-C selection in MD Settings, stealing strings from Options as a temporary workable solution.

I've sent https://codereview.chromium.org/2629573006/ to add an empty subpage.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c9c5ea2a110bd0721860bf2899f1dfecc150fc06

commit c9c5ea2a110bd0721860bf2899f1dfecc150fc06
Author: michaelpg <michaelpg@chromium.org>
Date: Sat Jan 14 19:41:25 2017

MD Settings: Dual-role charger selection

UI for Chromebooks that support dual-role devices to select which device to
charge from.

If a dedicated charger is attached, it will be used anyway, so we don't show the
dropdown menu.

If the Chrome device does not support dual-role devices, this row is not shown.

BUG= 633484 
R=stevenjb@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2629173004
Cr-Commit-Position: refs/heads/master@{#443801}

[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/app/settings_strings.grdp
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/resources/settings/device_page/device_page.html
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/resources/settings/device_page/device_page.js
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/resources/settings/device_page/device_page_browser_proxy.js
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/resources/settings/icons.html
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/ui/BUILD.gn
[add] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/ui/webui/settings/chromeos/device_power_handler.cc
[add] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/ui/webui/settings/chromeos/device_power_handler.h
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/ui/webui/settings/md_settings_localized_strings_provider.cc
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/browser/ui/webui/settings/md_settings_ui.cc
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/test/data/webui/settings/cr_settings_browsertest.js
[modify] https://crrev.com/c9c5ea2a110bd0721860bf2899f1dfecc150fc06/chrome/test/data/webui/settings/device_page_tests.js

is this fixed now?

oh, sorry, thought this was a specific crash bug.  carry on.

derat@ - What is the status of this, is it something we want to ship in 58?

I think that Michael has fixed this. It's a row rather than a full page, but it looks like we have parity between chrome://md-settings and chrome://settings in terms of the existing functionality.

I still plan to add a power subpage for  issue 633455 , but that's a non-urgent new feature and I have other stuff on my plate before I'll get to it.

OK, sgtm, thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8f2dc13d423abd8414e6bd5624aa516fcb1e683d

commit 8f2dc13d423abd8414e6bd5624aa516fcb1e683d
Author: derat <derat@chromium.org>
Date: Thu Mar 02 01:34:32 2017

chromeos: Add Power device page to chrome://md-settings.

Move the power row into its own subpage in anticipation of
adding additional settings.

BUG= 633484 , 633455 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2629573006
Cr-Commit-Position: refs/heads/master@{#454136}

[modify] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/app/settings_strings.grdp
[modify] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/browser/resources/settings/device_page/compiled_resources2.gyp
[modify] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/browser/resources/settings/device_page/device_page.html
[modify] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/browser/resources/settings/device_page/device_page.js
[add] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/browser/resources/settings/device_page/power.html
[add] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/browser/resources/settings/device_page/power.js
[modify] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/browser/resources/settings/route.js
[modify] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/browser/resources/settings/settings_resources.grd
[modify] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/browser/ui/webui/settings/md_settings_localized_strings_provider.cc
[modify] https://crrev.com/8f2dc13d423abd8414e6bd5624aa516fcb1e683d/chrome/test/data/webui/settings/device_page_tests.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/382a85f9de9bff0c3ec98dc2ba37d665f5848e70

commit 382a85f9de9bff0c3ec98dc2ba37d665f5848e70
Author: derat <derat@chromium.org>
Date: Wed Mar 15 02:47:19 2017

chromeos: Avoid NOTREACHED for MD settings power page.

Avoid hitting a NOTREACHED() when searching for "power" or
"device" at chrome://md-settings when power settings are
disabled.

BUG= 633484 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2751873002
Cr-Commit-Position: refs/heads/master@{#456966}

[modify] https://crrev.com/382a85f9de9bff0c3ec98dc2ba37d665f5848e70/chrome/browser/resources/settings/device_page/device_page.html

9460.30.0, 59.0.3071.41