[Password Manager] Add UMA stats to track interaction with synced accounts.

components/password_manager/core/browser/login_database.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_LOGIN_DATABASE_H_
 #define COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_LOGIN_DATABASE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 13 matching lines @@
 class LoginDatabase {
  public:
   LoginDatabase();
   virtual ~LoginDatabase();
 
   // Initialize the database with an sqlite file at the given path.
   // If false is returned, no other method should be called.
   bool Init(const base::FilePath& db_path);
 
   // Reports usage metrics to UMA.
-  void ReportMetrics();
+  void ReportMetrics(const std::string& sync_username);
 
   // Adds |form| to the list of remembered password forms. Returns the list of
   // changes applied ({}, {ADD}, {REMOVE, ADD}). If it returns {REMOVE, ADD}
   // then the REMOVE is associated with the form that was added. Thus only the
   // primary key columns contain the values associated with the removed form.
   PasswordStoreChangeList AddLogin(const autofill::PasswordForm& form);
 
   // Updates existing password form. Returns the list of applied changes
   // ({}, {UPDATE}). The password is looked up by the tuple {origin,
   // username_element, username_value, password_element, signon_realm}.
@@ skipping 103 matching lines @@
   sql::MetaTable meta_table_;
 
   PSLMatchingHelper psl_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(LoginDatabase);
 };
 
 }  // namespace password_manager
 
 #endif  // COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_LOGIN_DATABASE_H_