Add pretty-printing for PasswordStore::FormDigest

components/password_manager/core/browser/password_store.cc

Index: components/password_manager/core/browser/password_store.cc
diff --git a/components/password_manager/core/browser/password_store.cc b/components/password_manager/core/browser/password_store.cc
index c53814eb6c9a7471b2cfcdda8daa70467c7adedb..74146690c3ec93361e63ee73969133df1ed2766e 100644
--- a/components/password_manager/core/browser/password_store.cc
+++ b/components/password_manager/core/browser/password_store.cc
@@ -677,4 +677,11 @@ void PasswordStore::DestroySyncableService() {
   syncable_service_.reset();
 }
 
+std::ostream& operator<<(std::ostream& os,
+                         const PasswordStore::FormDigest& digest) {
+  return os << "FormDigest(scheme: " << digest.scheme
+            << ", signon_realm: " << digest.signon_realm
+            << ", origin: " << digest.origin << ")";
+}
+
 }  // namespace password_manager