From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Charles Kerr <charles@charleskerr.com>
Date: Sat, 28 Sep 2024 17:33:51 -0500
Subject: chore: partial revert of
 https://chromium-review.googlesource.com/c/chromium/src/+/5894233

The `CHECK_EQ()` being removed here is failing in the Chromium roll.
I experimented with backporting the `CHECK_EQ()` to `main` and it's
failing there as well, so some pre-existing behavior in Electron is
incompatible with this assertion.

I will file an upgrades-followup-task issue in Electron and try to
track down the source of this problem & figure out if we can fix it
by changing something in Electron.

diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index ce65cb2aec41faa58a1dfa43f5c1ac8e5bc66641..784a7536eec5a248e4725253c091b039047ff1ea 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -4821,9 +4821,6 @@ FrameTree* WebContentsImpl::CreateNewWindow(
   bool renderer_started_hidden =
       params.disposition == WindowOpenDisposition::NEW_BACKGROUND_TAB;
 
-  // While some guest types do not have a guest SiteInstance, the ones that
-  // don't all override WebContents creation above.
-  CHECK_EQ(source_site_instance->IsGuest(), IsGuest());
   bool is_guest = IsGuest();
 
   // We usually create the new window in the same BrowsingInstance (group of
