diff --git content/browser/child_process_security_policy_impl.cc content/browser/child_process_security_policy_impl.cc
index 9cd1ff2b9222..2f5264de68c4 100644
--- content/browser/child_process_security_policy_impl.cc
+++ content/browser/child_process_security_policy_impl.cc
@@ -1548,6 +1548,16 @@ bool ChildProcessSecurityPolicyImpl::CanAccessDataForOrigin(
         // DeclarativeApiTest.PersistRules.
         if (actual_process_lock.matches_scheme(url::kDataScheme))
           return true;
+
+        // Allow other schemes that are non-standard, non-local and WebSafe.
+        if (lock_url.is_valid() &&
+            !lock_url.IsStandard() &&
+            !base::Contains(url::GetLocalSchemes(),
+                            lock_url.scheme_piece()) &&
+            base::Contains(schemes_okay_to_request_in_any_process_,
+                           lock_url.scheme_piece())) {
+          return true;
+        }
       }
 
       // TODO(wjmaclean): We should update the ProcessLock comparison API to