From 99c496471b665ac81e42e71603f14b87cfc6b637 Mon Sep 17 00:00:00 2001
From: Paul Betts <paul@paulbetts.org>
Date: Tue, 20 Oct 2015 17:36:05 -0700
Subject: [PATCH] Allow WM_COPYDATA from all processes

---
 chromium_src/chrome/browser/process_singleton_win.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/chromium_src/chrome/browser/process_singleton_win.cc b/chromium_src/chrome/browser/process_singleton_win.cc
index b1008c37607b..0007b713b13b 100644
--- a/chromium_src/chrome/browser/process_singleton_win.cc
+++ b/chromium_src/chrome/browser/process_singleton_win.cc
@@ -293,6 +293,11 @@ bool ProcessSingleton::Create() {
         bool result = window_.CreateNamed(
             base::Bind(&ProcessLaunchNotification, notification_callback_),
             user_data_dir_.value());
+
+        // NB: Ensure that if the primary app gets started as elevated
+        // admin inadvertently, secondary windows running not as elevated
+        // will still be able to send messages
+        ::ChangeWindowMessageFilterEx(window_.hwnd(), WM_COPYDATA, MSGFLT_ALLOW, NULL);
         CHECK(result && window_.hwnd());
       }
     }