Implement 'secure origin whitelist' flag as a preference.

Also add an end-to-end browser test for the flag, to complement the
exising unit test for the feature.

This is in preparation to also support this flag as a policy
(based off the same preference), in cl 781634.

Bug: 
Change-Id: I64f8cfa772ce9f474f4dc43b5e58d7e87ba8f76e
Reviewed-on: https://chromium-review.googlesource.com/781632
Commit-Queue: Daniel Vogelheim <[email protected]>
Reviewed-by: Jochen Eisinger <[email protected]>
Cr-Commit-Position: refs/heads/master@{#518651}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 7202b12..8489a8c1 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -68,6 +68,7 @@
 #include "chrome/browser/ui/webui/print_preview/sticky_settings.h"
 #include "chrome/common/features.h"
 #include "chrome/common/pref_names.h"
+#include "chrome/common/secure_origin_whitelist.h"
 #include "components/autofill/core/browser/autofill_manager.h"
 #include "components/browsing_data/core/pref_names.h"
 #include "components/certificate_transparency/ct_policy_manager.h"
@@ -488,6 +489,7 @@
   PushMessagingAppIdentifier::RegisterProfilePrefs(registry);
   RegisterBrowserUserPrefs(registry);
   safe_browsing::RegisterProfilePrefs(registry);
+  secure_origin_whitelist::RegisterProfilePrefs(registry);
   SessionStartupPref::RegisterProfilePrefs(registry);
   signin::RegisterAccountConsistencyProfilePrefs(registry);
   syncer::SyncPrefs::RegisterProfilePrefs(registry);