xiaoyinh is this done? I remember seeing a CL go by.

Have a CL a while ago to preload polymer https://codereview.chromium.org/2628623002/, but it seems to have some issue with existing browser tests. I'm not sure what exactly happened though, will look into it more. 

Other than the browser test issue, seems like recent changes in settings once again break the options quick unlock overlay. Is there anything we can do to prevent this from happening?

Add a test?

md-settings is launching soonish though, so it doesn't make sense to spend a ton of time on testing though, since ROI will be low.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a7b35b6e3091d62218d6093633589997036e3b98

commit a7b35b6e3091d62218d6093633589997036e3b98
Author: xiaoyinh <xiaoyinh@chromium.org>
Date: Tue Feb 28 23:16:17 2017

This CL is trying to fix 2 issues:
1. Quick unlock configuration in options are importing polymer elements(lock_screen.html) created in settings, that includes importing all the elements that lock_screen.html depends on. So if there's new polymer elements imported in lock_screen.html, options wouldn't know where to find them, thus not able to load the lock_screen element. This CL makes options page know these newly added elements.

2. Trying to pre-load polymer elements in options page for better user experience.

BUG= 679795 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2691943005
Cr-Commit-Position: refs/heads/master@{#453733}

[modify] https://crrev.com/a7b35b6e3091d62218d6093633589997036e3b98/chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.js
[add] https://crrev.com/a7b35b6e3091d62218d6093633589997036e3b98/chrome/browser/resources/options/i18n_setup.html
[modify] https://crrev.com/a7b35b6e3091d62218d6093633589997036e3b98/chrome/browser/resources/options/options.html
[modify] https://crrev.com/a7b35b6e3091d62218d6093633589997036e3b98/chrome/browser/resources/options_resources.grd
[modify] https://crrev.com/a7b35b6e3091d62218d6093633589997036e3b98/chrome/browser/resources/settings/people_page/lock_screen.js
[modify] https://crrev.com/a7b35b6e3091d62218d6093633589997036e3b98/chrome/browser/ui/webui/options/browser_options_handler.cc
[modify] https://crrev.com/a7b35b6e3091d62218d6093633589997036e3b98/chrome/browser/ui/webui/options/options_ui.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/02b583cc874be794a9772f8b13230ab480058839

commit 02b583cc874be794a9772f8b13230ab480058839
Author: yutak <yutak@chromium.org>
Date: Wed Mar 01 09:12:33 2017

Revert of fix quick unlock config in options (patchset #8 id:140001 of https://codereview.chromium.org/2691943005/ )

Reason for revert:
This caused the following test to fail on ChromiumOS
debug bots. I've confirmed reverting this patch would
fix the errors on my local environment.

PolicyPrefIndicatorTestInstance/PolicyPrefIndicatorTest.CheckPolicyIndicators/26

https://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%281%29

Original issue's description:
> This CL is trying to fix 2 issues:
> 1. Quick unlock configuration in options are importing polymer elements(lock_screen.html) created in settings, that includes importing all the elements that lock_screen.html depends on. So if there's new polymer elements imported in lock_screen.html, options wouldn't know where to find them, thus not able to load the lock_screen element. This CL makes options page know these newly added elements.
>
> 2. Trying to pre-load polymer elements in options page for better user experience.
>
> BUG= 679795 
> CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
>
> Review-Url: https://codereview.chromium.org/2691943005
> Cr-Commit-Position: refs/heads/master@{#453733}
> Committed: https://chromium.googlesource.com/chromium/src/+/a7b35b6e3091d62218d6093633589997036e3b98

TBR=sammiequon@chromium.org,jdufault@chromium.org,dbeam@chromium.org,xiaoyinh@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= 679795 

Review-Url: https://codereview.chromium.org/2728563003
Cr-Commit-Position: refs/heads/master@{#453891}

[modify] https://crrev.com/02b583cc874be794a9772f8b13230ab480058839/chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.js
[delete] https://crrev.com/9dc4f6ff6d59eb2c27e3723a61e53f1430a9c192/chrome/browser/resources/options/i18n_setup.html
[modify] https://crrev.com/02b583cc874be794a9772f8b13230ab480058839/chrome/browser/resources/options/options.html
[modify] https://crrev.com/02b583cc874be794a9772f8b13230ab480058839/chrome/browser/resources/options_resources.grd
[modify] https://crrev.com/02b583cc874be794a9772f8b13230ab480058839/chrome/browser/resources/settings/people_page/lock_screen.js
[modify] https://crrev.com/02b583cc874be794a9772f8b13230ab480058839/chrome/browser/ui/webui/options/browser_options_handler.cc
[modify] https://crrev.com/02b583cc874be794a9772f8b13230ab480058839/chrome/browser/ui/webui/options/options_ui.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1a9f983b18d21da00d0e64647a0adbd91d7fbbb5

commit 1a9f983b18d21da00d0e64647a0adbd91d7fbbb5
Author: xiaoyinh <xiaoyinh@chromium.org>
Date: Fri Mar 03 21:14:24 2017

Fix quick unlock config in options
This CL is trying to fix the following issue:
Quick unlock configuration in options are importing polymer elements(lock_screen.html) created in settings, that
includes importing all the elements that lock_screen.html
depends on. So if there's new polymer elements imported in lock_screen.html, options wouldn't know where to find them,
thus not able to load the lock_screen element.
This CL makes options page know these newly added elements.

BUG= 679795 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2728173002
Cr-Commit-Position: refs/heads/master@{#454675}

[add] https://crrev.com/1a9f983b18d21da00d0e64647a0adbd91d7fbbb5/chrome/browser/resources/options/i18n_setup.html
[modify] https://crrev.com/1a9f983b18d21da00d0e64647a0adbd91d7fbbb5/chrome/browser/resources/options/options.html
[modify] https://crrev.com/1a9f983b18d21da00d0e64647a0adbd91d7fbbb5/chrome/browser/resources/options_resources.grd
[modify] https://crrev.com/1a9f983b18d21da00d0e64647a0adbd91d7fbbb5/chrome/browser/resources/settings/people_page/lock_screen.js
[modify] https://crrev.com/1a9f983b18d21da00d0e64647a0adbd91d7fbbb5/chrome/browser/ui/webui/options/browser_options_handler.cc
[modify] https://crrev.com/1a9f983b18d21da00d0e64647a0adbd91d7fbbb5/chrome/browser/ui/webui/options/options_ui.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1cb6c0e588f5e30463c81be7a4a404911b5e3b6d

commit 1cb6c0e588f5e30463c81be7a4a404911b5e3b6d
Author: xiaoyinh <xiaoyinh@chromium.org>
Date: Wed Mar 08 01:36:23 2017

preload polymer elements in options page

This CL is trying:
1. Pre-load polymer elements in options page for better
user experience.

2. Disable polymer pre-loading in browser_test to avoid racing.

BUG= 679795 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2728453003
Cr-Commit-Position: refs/heads/master@{#455327}

[modify] https://crrev.com/1cb6c0e588f5e30463c81be7a4a404911b5e3b6d/chrome/browser/resources/options/chromeos/quick_unlock_configure_overlay.js
[modify] https://crrev.com/1cb6c0e588f5e30463c81be7a4a404911b5e3b6d/chrome/browser/ui/webui/options/browser_options_handler.cc
[modify] https://crrev.com/1cb6c0e588f5e30463c81be7a4a404911b5e3b6d/chrome/browser/ui/webui/options/browser_options_handler.h
[modify] https://crrev.com/1cb6c0e588f5e30463c81be7a4a404911b5e3b6d/chrome/test/base/in_process_browser_test.cc