Implement Federated PSL Matches in Native Backends

components/password_manager/core/browser/psl_matching_helper.cc

Index: components/password_manager/core/browser/psl_matching_helper.cc
diff --git a/components/password_manager/core/browser/psl_matching_helper.cc b/components/password_manager/core/browser/psl_matching_helper.cc
index 8790e8a7c6411aefa0efacc1ae0547d0fe92991a..02bccbe4b97a11dd755ef61f5326d64b2c5e8cff 100644
--- a/components/password_manager/core/browser/psl_matching_helper.cc
+++ b/components/password_manager/core/browser/psl_matching_helper.cc
@@ -5,6 +5,7 @@
 #include "components/password_manager/core/browser/psl_matching_helper.h"
 
 #include <memory>
+#include <ostream>
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
@@ -17,6 +18,53 @@ using autofill::PasswordForm;
 
 namespace password_manager {
 
+std::ostream& operator<<(std::ostream& out, MatchResult result) {
+  switch (result) {
+    case MatchResult::NO_MATCH:
+      return out << "No Match";
+    case MatchResult::EXACT_MATCH:
+      return out << "Exact Match";
+    case MatchResult::PSL_MATCH:
+      return out << "PSL Match";
+    case MatchResult::FEDERATED_MATCH:
+      return out << "Federated Match";
+    case MatchResult::FEDERATED_PSL_MATCH:
+      return out << "Federated PSL Match";
+  }
+  // This should never be reached, it is simply here to suppress compiler
+  // warnings.
+  return out;
+}
+
+MatchResult GetMatchResult(const PasswordForm& form,
+                           const PasswordStore::FormDigest& form_digest) {
+  if (form.signon_realm == form_digest.signon_realm)
+    return MatchResult::EXACT_MATCH;
+
+  // PSL and federated matches only apply to HTML forms.
+  if (form_digest.scheme != PasswordForm::SCHEME_HTML ||
+      form.scheme != PasswordForm::SCHEME_HTML)
+    return MatchResult::NO_MATCH;
+
+  const bool allow_psl_match = ShouldPSLDomainMatchingApply(
+      GetRegistryControlledDomain(GURL(form_digest.signon_realm)));
+  const bool allow_federated_match = !form.federation_origin.unique();
+
+  if (allow_psl_match &&
+      IsPublicSuffixDomainMatch(form.signon_realm, form_digest.signon_realm))
+    return MatchResult::PSL_MATCH;
+
+  if (allow_federated_match &&
+      IsFederatedMatch(form.signon_realm, form_digest.origin))
+    return MatchResult::FEDERATED_MATCH;
+
+  if (allow_psl_match && allow_federated_match &&
+      IsFederatedPSLMatch(form.signon_realm, form_digest.origin))
+    return MatchResult::FEDERATED_PSL_MATCH;
+
+  return MatchResult::NO_MATCH;
+}
+
 bool ShouldPSLDomainMatchingApply(
     const std::string& registry_controlled_domain) {
   return !registry_controlled_domain.empty() &&