[Clean up] Clean up some methods in PasswordManagerClient

components/password_manager/core/browser/password_form_manager_unittest.cc

 // Copyright (c) 2012 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.
 
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/testing_pref_service.h"
 #include "base/run_loop.h"
@@ skipping 84 matching lines @@
                                            true);
   }
 
   bool ShouldFilterAutofillResult(const autofill::PasswordForm& form) override {
     if (form == form_to_filter_)
       return true;
     return false;
   }
 
   PrefService* GetPrefs() override { return &prefs_; }
-  PasswordStore* GetPasswordStore() override { return password_store_; }
+  PasswordStore* GetPasswordStore() const override { return password_store_; }
 
   void SetFormToFilter(const autofill::PasswordForm& form) {
     form_to_filter_ = form;
   }
 
   MockPasswordManagerDriver* mock_driver() { return driver_.get(); }
 
   base::WeakPtr<PasswordManagerDriver> driver() { return driver_->AsWeakPtr(); }
 
   autofill::AutofillManager* GetAutofillManagerForMainFrame() override {
@@ skipping 1251 matching lines @@
   form_manager.OnGetPasswordStoreResults(simulated_results.Pass());
   EXPECT_EQ(1u, form_manager.best_matches().size());
   EXPECT_EQ(form_manager.preferred_match(),
             form_manager.best_matches().begin()->second);
   // Make sure to access all fields of preferred_match; this way if it was
   // deleted, ASAN might notice it.
   PasswordForm dummy(*form_manager.preferred_match());
 }
 
 }  // namespace password_manager