Note that we'll need to update https://www.chromium.org/Home/chromium-security/site-isolation accordingly.  I can probably help with that once the CLs land.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/738a88dfe05e3f273cd3150f6f75dbecd78cba78

commit 738a88dfe05e3f273cd3150f6f75dbecd78cba78
Author: Lukasz Anforowicz <lukasza@chromium.org>
Date: Mon Nov 05 19:19:34 2018

Drop "trials" from ...DisableSiteIsolationTrials... where backcompatible

This CL edits descriptions and comments related to the
--disable-site-isolation-trials switch.  The switch is implemented and
used in a way that disables not only site isolation trials, but also
opts out of the default site isolation mode (i.e. out of
site-per-process mode that is the default on desktop since M67).

The CL avoids editing the *name* of the switch to avoid backcompatibility
problems around chrome://flags and/or test tools.  There are no intended
behavior changes except for different description texts for the
enterprise policy and chrome://flags.

Change-Id: Ia2076c4120d159f9d80e7d578ea0e673fdfda759
Bug: 901522
Reviewed-on: https://chromium-review.googlesource.com/c/1315535
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605409}
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/chrome/browser/about_flags.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/chrome/browser/chrome_browser_main.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/chrome/browser/chrome_content_browser_client_browsertest.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/chrome/browser/chromeos/login/session/user_session_manager.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/chrome/browser/policy/site_isolation_policy_browsertest.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/components/policy/resources/policy_templates.json
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/content/browser/isolated_origin_browsertest.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/content/public/browser/site_isolation_policy.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/content/public/common/content_switches.cc
[modify] https://crrev.com/738a88dfe05e3f273cd3150f6f75dbecd78cba78/content/public/common/content_switches.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4284042094c169d1985bc0d769b5794e03707071

commit 4284042094c169d1985bc0d769b5794e03707071
Author: Lukasz Anforowicz <lukasza@chromium.org>
Date: Mon Nov 05 21:49:22 2018

Remove chrome://flags/#enable-site-per-process on desktop platforms

site-per-process has shipped on desktop platforms in M67.
Therefore, chrome://flags/#enable-site-per-process is not needed on
desktop platforms (since the default already is to enable
site-per-process).

Bug: 901522
Change-Id: I0d0bceb3706453683362ae4c7efa41d78a9104d8
Reviewed-on: https://chromium-review.googlesource.com/c/1316649
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605480}
[modify] https://crrev.com/4284042094c169d1985bc0d769b5794e03707071/chrome/browser/about_flags.cc
[modify] https://crrev.com/4284042094c169d1985bc0d769b5794e03707071/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/4284042094c169d1985bc0d769b5794e03707071/chrome/browser/flag_descriptions.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c25394981936745cd8ea601d34b0b36a14a52891

commit c25394981936745cd8ea601d34b0b36a14a52891
Author: Lukasz Anforowicz <lukasza@chromium.org>
Date: Wed Nov 28 17:29:07 2018

Providing metadata for Site-Isolation-related chrome://flags

Bug: 901522
Change-Id: I6c0f672a3544641bc44b218773e4db9fb1fa64b2
Reviewed-on: https://chromium-review.googlesource.com/c/1340579
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611751}
[modify] https://crrev.com/c25394981936745cd8ea601d34b0b36a14a52891/chrome/browser/flag-metadata.json