[Password Manager] Add UMA stats for custom passphrase users.

components/password_manager/core/browser/login_database.h

Index: components/password_manager/core/browser/login_database.h
diff --git a/components/password_manager/core/browser/login_database.h b/components/password_manager/core/browser/login_database.h
index 0ea86e535f6cc9ee0b71b5d79db6ae80c524991f..6cdf7a4716ff237092161aee08fa863901ec93d9 100644
--- a/components/password_manager/core/browser/login_database.h
+++ b/components/password_manager/core/browser/login_database.h
@@ -18,6 +18,8 @@
 
 namespace password_manager {
 
+class PasswordManagerClient;
+
 // Interface to the database storage of login information, intended as a helper
 // for PasswordStore on platforms that need internal storage of some or all of
 // the login information.
@@ -31,7 +33,7 @@ class LoginDatabase {
   bool Init(const base::FilePath& db_path);
 
   // Reports usage metrics to UMA.
-  void ReportMetrics(const std::string& sync_username);
+  void ReportMetrics(PasswordManagerClient* client);
 
   // Adds |form| to the list of remembered password forms. Returns the list of
   // changes applied ({}, {ADD}, {REMOVE, ADD}). If it returns {REMOVE, ADD}