electron/patches/chromium/extend_apply_webpreferences.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samuel Attard <sattard@slack-corp.com>
Date: Mon, 8 Mar 2021 16:27:39 -0800
Subject: extend ApplyWebPreferences with Electron-specific logic

On macOS, popup menus are rendered by the main process by default.
This causes problems in OSR, since when the popup is rendered separately,
it won't be captured in the rendered image.
Offscreen can be updated at runtime, as such we need to apply the
turn on/off ExternalPopupMenu in the ApplyPreferences method.
There is no current way to attach an observer to these prefs so patching
is our only option.

Ideally we could add an embedder observer pattern here but that can be
done in future work.

diff --git a/third_party/blink/renderer/core/exported/web_view_impl.cc b/third_party/blink/renderer/core/exported/web_view_impl.cc
index 5e0df4263d176b699e940f20d79e90e5b3259014..d9125c7905cb4e5dd00c3d5c05c87d45079cca94 100644
--- a/third_party/blink/renderer/core/exported/web_view_impl.cc
+++ b/third_party/blink/renderer/core/exported/web_view_impl.cc
@@ -1882,6 +1882,8 @@ void WebView::ApplyWebPreferences(const web_pref::WebPreferences& prefs,
 #if BUILDFLAG(IS_MAC)
   web_view_impl->SetMaximumLegibleScale(
       prefs.default_maximum_page_scale_factor);
+  web_view_impl->GetChromeClient().SetUseExternalPopupMenusForTesting(
+      !prefs.offscreen);
 #endif
 
 #if BUILDFLAG(IS_WIN)