Add enterprise policy to disable mixed form warnings

Disables both the on-form warning (kAutofillPreventMixedFormsFilling)
and the on submit interstitial (kInsecureFormSubmissionInterstitial).

Bug: 1106545
Change-Id: I85ece8018b06de600a03d28821102bfabb4ff0a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2305239
Commit-Queue: Carlos IL <[email protected]>
Reviewed-by: Julian Pastarmov <[email protected]>
Reviewed-by: Emily Stark <[email protected]>
Reviewed-by: Dominic Battré <[email protected]>
Cr-Commit-Position: refs/heads/master@{#792087}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 27cfac9b..1ee903b 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -137,6 +137,7 @@
 #include "components/rappor/rappor_service_impl.h"
 #include "components/safe_browsing/core/common/safe_browsing_prefs.h"
 #include "components/search_engines/template_url_prepopulate_data.h"
+#include "components/security_interstitials/content/insecure_form_blocking_page.h"
 #include "components/security_interstitials/content/stateful_ssl_host_state_delegate.h"
 #include "components/sessions/core/session_id_generator.h"
 #include "components/signin/public/identity_manager/identity_manager.h"
@@ -923,6 +924,8 @@
   safe_browsing::RegisterProfilePrefs(registry);
   blocked_content::SafeBrowsingTriggeredPopupBlocker::RegisterProfilePrefs(
       registry);
+  security_interstitials::InsecureFormBlockingPage::RegisterProfilePrefs(
+      registry);
   SessionStartupPref::RegisterProfilePrefs(registry);
   SharingSyncPreference::RegisterProfilePrefs(registry);
   sync_sessions::SessionSyncPrefs::RegisterProfilePrefs(registry);