The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/206fca8624030e5ecc35a29a8cef623d3bcd2efe

commit 206fca8624030e5ecc35a29a8cef623d3bcd2efe
Author: Yue Li <updowndota@chromium.org>
Date: Tue Mar 20 19:02:08 2018

Prototype for Assistant OptIn WebUI

Design document: go/assistant-consent-flow-ui

This is a prototype for a new WebUI controller for the Assistant OptIn Flow.
The old flow is inside the CrOS OOBE.

The new WebUI controller is independent to the login host, but still share
styles with login UI.

For now it only contains the value prop page, since the design of the
other pages are still TBD.

Bug:  814048 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Idac1e2c61505e169f53fd8f3ef32280cb456d672
Reviewed-on: https://chromium-review.googlesource.com/927267
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Commit-Queue: Yue Li <updowndota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544466}
[modify] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/browser_resources.grd
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/resources/chromeos/assistant_optin/assistant_optin.css
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/resources/chromeos/assistant_optin/assistant_optin.html
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/resources/chromeos/assistant_optin/assistant_optin.js
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/resources/chromeos/assistant_optin/assistant_value_prop.css
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/resources/chromeos/assistant_optin/assistant_value_prop.html
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/resources/chromeos/assistant_optin/assistant_value_prop.js
[modify] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/ui/BUILD.gn
[modify] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/ui/webui/chromeos/assistant_optin/assistant_optin_screen_exit_code.h
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/ui/webui/chromeos/assistant_optin/assistant_optin_ui.cc
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/ui/webui/chromeos/assistant_optin/assistant_optin_ui.h
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/ui/webui/chromeos/assistant_optin/value_prop_screen_handler.cc
[add] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/browser/ui/webui/chromeos/assistant_optin/value_prop_screen_handler.h
[modify] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/common/webui_url_constants.cc
[modify] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/chrome/common/webui_url_constants.h
[modify] https://crrev.com/206fca8624030e5ecc35a29a8cef623d3bcd2efe/extensions/common/api/_api_features.json

New tracking bug for native Assistant OOBE: b/78190629