The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3f92fd3d49f00789495bff44712a5dcb7fa1ff85

commit 3f92fd3d49f00789495bff44712a5dcb7fa1ff85
Author: dschuyler <dschuyler@chromium.org>
Date: Thu Dec 22 23:39:01 2016

[MD settings] lighter weight initializer for protocol handler enabled messages

This CL adds an initializer call for the Protocol Handlers handler so
that updates for the enabled/disabled state will be sent without getting
the whole list of protocol handlers.

BUG= 676527 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2598893002
Cr-Commit-Position: refs/heads/master@{#440543}

[modify] https://crrev.com/3f92fd3d49f00789495bff44712a5dcb7fa1ff85/chrome/browser/resources/settings/site_settings/protocol_handlers.html
[modify] https://crrev.com/3f92fd3d49f00789495bff44712a5dcb7fa1ff85/chrome/browser/resources/settings/site_settings/protocol_handlers.js
[modify] https://crrev.com/3f92fd3d49f00789495bff44712a5dcb7fa1ff85/chrome/browser/resources/settings/site_settings/site_settings_prefs_browser_proxy.js
[modify] https://crrev.com/3f92fd3d49f00789495bff44712a5dcb7fa1ff85/chrome/browser/ui/webui/settings/protocol_handlers_handler.cc
[modify] https://crrev.com/3f92fd3d49f00789495bff44712a5dcb7fa1ff85/chrome/browser/ui/webui/settings/protocol_handlers_handler.h
[modify] https://crrev.com/3f92fd3d49f00789495bff44712a5dcb7fa1ff85/chrome/test/data/webui/settings/protocol_handlers_tests.js
[modify] https://crrev.com/3f92fd3d49f00789495bff44712a5dcb7fa1ff85/chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/40a8332622f24dae5bab19205fde65e8c5c79448

commit 40a8332622f24dae5bab19205fde65e8c5c79448
Author: dschuyler <dschuyler@chromium.org>
Date: Thu Jan 05 01:47:53 2017

[MD settings] update protocol handler setting in content settings

This CL fixes an issue on the content settings page. The Protocol
Handlers row is updated different from all the other sections in that
list and is not currently updated correctly. This CL fixes the Protocol
Handlers sub-text on that page so that it's correct on first load and
continues to update if changes are made to the enabled state of Protocol
Handlers.

BUG= 676527 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2599913002
Cr-Commit-Position: refs/heads/master@{#441552}

[modify] https://crrev.com/40a8332622f24dae5bab19205fde65e8c5c79448/chrome/browser/resources/settings/site_settings_page/site_settings_page.js