Is this because of your latest patch which doesn't open on a redirect navigation? (Since http://calendar.google.com will redirect to https?)

Could be tricky because we'll want to handle some but not all redirects. We could just leave it alone (links should go into https).

Fixed the description, since, as you point out, it wouldn't open the PWA. (yes, clicking the http link will not open the PWA).

The http page does redirect to https but we don't get notified about this redirection so we don't open the PWA. I looked at the Network tab in dev tools and we seem to be getting a 301 response from the server. I'm not sure if that's what's causing the issue.

This also happens when visiting http variants of github pages :(

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d49f0a8e0a476109cc6836ac13bb423b064a3933

commit d49f0a8e0a476109cc6836ac13bb423b064a3933
Author: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Date: Wed Oct 11 00:20:42 2017

desktop-pwas: Redirect client-side and server-side redirectiosn to installed PWAs

Before, clicking a link to "http://calendar.google.com" would redirect to
"https://calendar.google.com" but the installed PWA for calendar would not open.
This is because the initial navigation's URL did not match the PWAs origin.

This patch makes it so that we also take redirects into consideration for
redirecting to installed PWAs. So clicking on "http://calendar.google.com",
which eventually redirects to "https://calendar.google.com", will open
the installed Calendar PWA.

Bug:  754082 
Change-Id: I9c1cde548aa2810835bcc8564c66de9416db0607
Reviewed-on: https://chromium-review.googlesource.com/706742
Reviewed-by: Ben Wells <benwells@chromium.org>
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#507834}
[modify] https://crrev.com/d49f0a8e0a476109cc6836ac13bb423b064a3933/chrome/browser/extensions/bookmark_app_navigation_throttle.cc
[modify] https://crrev.com/d49f0a8e0a476109cc6836ac13bb423b064a3933/chrome/browser/extensions/bookmark_app_navigation_throttle.h
[modify] https://crrev.com/d49f0a8e0a476109cc6836ac13bb423b064a3933/chrome/browser/extensions/bookmark_app_navigation_throttle_browsertest.cc

The latest patch fixes server-side redirection.

Client-side redirections came up during review as they will leave the existing tab in an intermediate step. The latest patch doesn't change their behavior i.e. we've always opened the app for them and will continue to do so. That said we should keep an eye out to see if the experience for client-side redirections is not good enough.