The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/edc8f6f4c5e7a5d90516b931bd7dddc9108d7c71

commit edc8f6f4c5e7a5d90516b931bd7dddc9108d7c71
Author: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Date: Tue Nov 28 05:22:11 2017

desktop-pwas: When in an App window, SSL interstitials proceed to a browser tab

Desktop PWAs should not be allowed to run if there is a problem with
their certificate. So when users click proceed on an interstitial
we open a new tab in a regular Chrome window and proceed there.

To make transient interstitial tests work, this patch also changes
ProceedThroughInterstitial to use SendInterstitialCommand instead
of InterstitialPage::Proceed for non-committed interstitials.
Directly calling InterstitialPage::Proceed skips calling through
to SSLErrorControllerClient which is where the logic to open the
app window is.

Bug: 779857
Change-Id: If90a7f56076977b8cfaf5b3837a0a35c8dbe54cc
Reviewed-on: https://chromium-review.googlesource.com/786873
Reviewed-by: Emily Stark <estark@chromium.org>
Reviewed-by: Matt Giuca <mgiuca@chromium.org>
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519575}
[modify] https://crrev.com/edc8f6f4c5e7a5d90516b931bd7dddc9108d7c71/chrome/browser/ssl/ssl_browsertest.cc
[modify] https://crrev.com/edc8f6f4c5e7a5d90516b931bd7dddc9108d7c71/chrome/browser/ssl/ssl_error_controller_client.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ca30c84579095a6ef6fdd653527725621f0b32a3

commit ca30c84579095a6ef6fdd653527725621f0b32a3
Author: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Date: Wed Feb 21 23:38:32 2018

content: Allow NavigationThrottles to specify a error page when canceling navigations

Plumb error page contents for canceled start requests, redirect
requests and responses. This allows Navigation Throttles to cancel a
navigation in WillStartRequest, WillRedirectRequest and
WillProcessResponse with a custom error page.

This CL is based on https://crrev.com/c/768930/10

Bug: 779857
Change-Id: I3d477993674f928cb61fb219c846f3db211d122c
Reviewed-on: https://chromium-review.googlesource.com/816457
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: Camille Lamy <clamy@chromium.org>
Reviewed-by: Emily Stark <estark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#538255}
[modify] https://crrev.com/ca30c84579095a6ef6fdd653527725621f0b32a3/content/browser/frame_host/navigation_handle_impl_browsertest.cc
[modify] https://crrev.com/ca30c84579095a6ef6fdd653527725621f0b32a3/content/browser/frame_host/navigation_request.cc
[modify] https://crrev.com/ca30c84579095a6ef6fdd653527725621f0b32a3/content/browser/frame_host/navigation_request.h
[modify] https://crrev.com/ca30c84579095a6ef6fdd653527725621f0b32a3/content/public/browser/navigation_throttle.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e4a680d8df7cc8831a83f4023aee57acc62784e0

commit e4a680d8df7cc8831a83f4023aee57acc62784e0
Author: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Date: Tue Feb 27 03:42:37 2018

desktop-pwas: Always show an interstitial if in an app window

This covers the case where a user proceeded through an
interstitial in the past and then opened the app. In a regular tab,
we wouldn't show the interstitial but since Desktop PWAs always have
to be secure we show an interstitial.

Bug: 779857
Change-Id: I0efef48f38ef51d7e5016be07829971d44656e6c
Reviewed-on: https://chromium-review.googlesource.com/936922
Reviewed-by: Emily Stark <estark@chromium.org>
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539392}
[modify] https://crrev.com/e4a680d8df7cc8831a83f4023aee57acc62784e0/chrome/browser/ssl/ssl_browsertest.cc
[modify] https://crrev.com/e4a680d8df7cc8831a83f4023aee57acc62784e0/chrome/browser/ssl/ssl_error_navigation_throttle.cc
[modify] https://crrev.com/e4a680d8df7cc8831a83f4023aee57acc62784e0/chrome/browser/ssl/ssl_error_navigation_throttle.h

Gio, is this done now (per the above 3 CLs)?

Bumping up to P1 since it's security UX. Please mark Fixed if done.

This is blocked on 448486. I'll check with estark and see if they are still targeting 67. Otherwise we might have to work around some issues.

Removing label. We decided to just show the location bar for now. Once issue 448486 is fixed, this will also be fixed.