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

components/password_manager/core/browser/test_password_store.h

Index: components/password_manager/core/browser/test_password_store.h
diff --git a/components/password_manager/core/browser/test_password_store.h b/components/password_manager/core/browser/test_password_store.h
index 7c44b0ba27cc630dcdd580f58d893838f8bd97a4..15a334f5185205c24a85e06bb67c93168bab0a86 100644
--- a/components/password_manager/core/browser/test_password_store.h
+++ b/components/password_manager/core/browser/test_password_store.h
@@ -58,7 +58,7 @@ class TestPasswordStore : public PasswordStore {
   virtual void WrapModificationTask(ModificationTask task) override;
 
   // Unused portions of PasswordStore interface
-  virtual void ReportMetricsImpl(const std::string& sync_username) override {}
+  virtual void ReportMetricsImpl(PasswordManagerClient* client) override {}
   virtual PasswordStoreChangeList RemoveLoginsCreatedBetweenImpl(
       base::Time begin,
       base::Time end) override;