diff -up chromium-52.0.2743.82/chrome/browser/first_run/first_run_internal_linux.cc.etc chromium-52.0.2743.82/chrome/browser/first_run/first_run_internal_linux.cc
--- chromium-52.0.2743.82/chrome/browser/first_run/first_run_internal_linux.cc.etc	2016-08-03 10:15:57.980692109 +0200
+++ chromium-52.0.2743.82/chrome/browser/first_run/first_run_internal_linux.cc	2016-08-03 10:16:44.553325229 +0200
@@ -19,9 +19,9 @@ bool IsOrganicFirstRun() {
 
 base::FilePath MasterPrefsPath() {
   // The standard location of the master prefs is next to the chrome binary.
+  // ...but we patch it to use /etc/chromium
   base::FilePath master_prefs;
-  if (!PathService::Get(base::DIR_EXE, &master_prefs))
-    return base::FilePath();
+  master_prefs = base::FilePath("/etc/chromium");
   return master_prefs.AppendASCII(installer::kDefaultMasterPrefs);
 }