I will start by doing this for chrome://md-settings.

blocked on https://github.com/PolymerElements/paper-item/issues/85

In Settings, the remaining <paper-item> uses are:

* site settings
* CUPS printers
* bluetooth list

Should be straightforward to replace them with buttons, but may also involve dealing with <iron-dropdown>s.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3188c5dbeaac9424446fb392f02756cb4374f9f3

commit 3188c5dbeaac9424446fb392f02756cb4374f9f3
Author: dpapad <dpapad@chromium.org>
Date: Fri Oct 21 01:16:40 2016

MD Settings: Migrate cups_printers_list.html to settings-action-menu.

BUG= 639718 , 603976 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://chromiumcodereview.appspot.com/2427323003
Cr-Commit-Position: refs/heads/master@{#426672}

[modify] https://crrev.com/3188c5dbeaac9424446fb392f02756cb4374f9f3/chrome/browser/resources/settings/printing_page/compiled_resources2.gyp
[modify] https://crrev.com/3188c5dbeaac9424446fb392f02756cb4374f9f3/chrome/browser/resources/settings/printing_page/cups_printers_list.html
[modify] https://crrev.com/3188c5dbeaac9424446fb392f02756cb4374f9f3/chrome/browser/resources/settings/printing_page/cups_printers_list.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6d273cd75ba1d15a782fd06677560bf54fade3f2

commit 6d273cd75ba1d15a782fd06677560bf54fade3f2
Author: scottchen <scottchen@chromium.org>
Date: Thu Nov 10 21:37:56 2016

change site-settings -> usb-device to use cr-action-menu instead of paper-menu

This CL is part of the effort to move off of paper-item which is known to have performance issues.
Note for future improvement: dpapad@ and I noticed that there's only a remove button in the dropdown menu, so we can probably replace it with just an "X" button.

BUG= 603976 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2480843003
Cr-Commit-Position: refs/heads/master@{#431362}

[modify] https://crrev.com/6d273cd75ba1d15a782fd06677560bf54fade3f2/chrome/browser/resources/settings/site_settings/compiled_resources2.gyp
[modify] https://crrev.com/6d273cd75ba1d15a782fd06677560bf54fade3f2/chrome/browser/resources/settings/site_settings/usb_devices.html
[modify] https://crrev.com/6d273cd75ba1d15a782fd06677560bf54fade3f2/chrome/browser/resources/settings/site_settings/usb_devices.js
[modify] https://crrev.com/6d273cd75ba1d15a782fd06677560bf54fade3f2/chrome/test/data/webui/settings/cr_settings_browsertest.js
[modify] https://crrev.com/6d273cd75ba1d15a782fd06677560bf54fade3f2/chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js
[add] https://crrev.com/6d273cd75ba1d15a782fd06677560bf54fade3f2/chrome/test/data/webui/settings/usb_devices_tests.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dcb5fc9af2549a795edf7e67d596e261364a948b

commit dcb5fc9af2549a795edf7e67d596e261364a948b
Author: scottchen <scottchen@chromium.org>
Date: Tue Nov 15 01:46:06 2016

Make setting's protocol handler use cr-action-menu instead of paper-item.

BUG= 603976 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2500513003
Cr-Commit-Position: refs/heads/master@{#432048}

[modify] https://crrev.com/dcb5fc9af2549a795edf7e67d596e261364a948b/chrome/browser/resources/settings/site_settings/compiled_resources2.gyp
[modify] https://crrev.com/dcb5fc9af2549a795edf7e67d596e261364a948b/chrome/browser/resources/settings/site_settings/protocol_handlers.html
[modify] https://crrev.com/dcb5fc9af2549a795edf7e67d596e261364a948b/chrome/browser/resources/settings/site_settings/protocol_handlers.js
[modify] https://crrev.com/dcb5fc9af2549a795edf7e67d596e261364a948b/chrome/browser/resources/settings/site_settings/usb_devices.html
[modify] https://crrev.com/dcb5fc9af2549a795edf7e67d596e261364a948b/chrome/test/data/webui/settings/cr_settings_browsertest.js
[add] https://crrev.com/dcb5fc9af2549a795edf7e67d596e261364a948b/chrome/test/data/webui/settings/protocol_handlers_tests.js
[modify] https://crrev.com/dcb5fc9af2549a795edf7e67d596e261364a948b/chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js
[modify] https://crrev.com/dcb5fc9af2549a795edf7e67d596e261364a948b/chrome/test/data/webui/settings/usb_devices_tests.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2507bc013bac421e3775d7119322aced956b633a

commit 2507bc013bac421e3775d7119322aced956b633a
Author: scottchen <scottchen@chromium.org>
Date: Fri Nov 18 20:11:32 2016

remove unnecessary paper-item dependency from site_details.

We're trying to remove all paper-item dependency for performance reasons, and a div with list-item class can achieve the desired visual effects and seems more suitable. I also removed the hidden attribute because its parent element has the exact same hidden condition, so seems redundant to have both.

BUG= 603976 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2512613003
Cr-Commit-Position: refs/heads/master@{#433278}

[modify] https://crrev.com/2507bc013bac421e3775d7119322aced956b633a/chrome/browser/resources/settings/site_settings/site_details.html
[modify] https://crrev.com/2507bc013bac421e3775d7119322aced956b633a/chrome/test/data/webui/settings/site_details_tests.js

I've removed paper-item dependency from
- site_details
- usb_devices
- protocol_handlers

The rest of paper-item usage are in chromeos code, and I currently don't have the machine to build chromeOS yet, so anyone feel free to pick this up.

Marking as Chrome OS-only.

MD History doesn't use paper-item anymore, so I'm removing the History component

xdai@ - The remaining paper-item is in cups_add_printer_dialog_util.html:

https://cs.chromium.org/chromium/src/chrome/browser/resources/settings/printing_page/cups_add_printer_dialog_util.html?q=paper-item+file:%5Esrc/chrome/browser/resources/settings/printing_page/&sq=package:chromium&l=31&dr=C

Could you remove this sometime during the 58 cycle? We'd like to eliminate paper-item before shipping.

Sure

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6477751a2c1a2c3fba3ba77917efd51f48b0e2ab

commit 6477751a2c1a2c3fba3ba77917efd51f48b0e2ab
Author: dpapad <dpapad@chromium.org>
Date: Tue Feb 07 03:18:37 2017

MD Settings: Remove last usage of paper-item.

 - Replace <paper-item> usage with a styled <button>.
 - Remove all references to paper-item shared style files.
 - Move iron-dropdown rules to cups_add_printer_dialog_util.html, since
   it has the only usage of iron-dropdown.

BUG= 603976 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2677863004
Cr-Commit-Position: refs/heads/master@{#448534}

[modify] https://crrev.com/6477751a2c1a2c3fba3ba77917efd51f48b0e2ab/chrome/browser/resources/settings/printing_page/cups_add_printer_dialog_util.html
[modify] https://crrev.com/6477751a2c1a2c3fba3ba77917efd51f48b0e2ab/chrome/browser/resources/settings/settings_shared_css.html
[modify] https://crrev.com/6477751a2c1a2c3fba3ba77917efd51f48b0e2ab/chrome/browser/resources/settings/settings_vars_css.html

Close this since the last usage of paper-item was removed in #18.