Prevent prefs_registrar unsubscribe from destroyed pref_service

chrome/browser/ui/webui/options/preferences_browsertest.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_OPTIONS_PREFERENCES_BROWSERTEST_H_
 #define CHROME_BROWSER_UI_WEBUI_OPTIONS_PREFERENCES_BROWSERTEST_H_
 
+#include <memory>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "components/policy/core/common/mock_configuration_policy_provider.h"
 #include "components/policy/core/common/policy_types.h"
 #include "components/prefs/pref_change_registrar.h"
@@ skipping 13 matching lines @@
 // Tests verifying that the JavaScript Preferences class, the underlying C++
 // CoreOptionsHandler and the specialized classes handling Chrome OS device and
 // proxy prefs behave correctly.
 class PreferencesBrowserTest : public InProcessBrowserTest {
  public:
   PreferencesBrowserTest();
   ~PreferencesBrowserTest() override;
 
   // InProcessBrowserTest implementation:
   void SetUpOnMainThread() override;
+  void TearDownOnMainThread() override;
 
   void OnPreferenceChanged(const std::string& pref_name);
 
  protected:
   MOCK_METHOD1(OnCommit, void(const PrefService::Preference*));
 
+  // The pref service that holds the current pref values in the C++ backend.
+  PrefService* pref_service();
+
   void SetUpPrefs();
 
   // InProcessBrowserTest implementation:
   void SetUpInProcessBrowserTestFixture() override;
 
   // Sets user policies through the mock policy provider.
   void SetUserPolicies(const std::vector<std::string>& names,
                        const std::vector<base::Value*>& values,
                        policy::PolicyLevel level);
   // Clears user policies.
@@ skipping 111 matching lines @@
 
   // The current tab's render view host, required to inject JavaScript code into
   // the tab.
   content::RenderViewHost* render_view_host_;
 
   // Mock policy provider for both user and device policies.
   policy::MockConfigurationPolicyProvider policy_provider_;
 
   // Pref change registrar that detects changes to user-modified pref values
   // made in the C++ backend by the JavaScript Preferences class.
-  PrefChangeRegistrar pref_change_registrar_;
-
-  // The pref service that holds the current pref values in the C++ backend.
-  PrefService* pref_service_;
+  std::unique_ptr<PrefChangeRegistrar> pref_change_registrar_;
 
   // The prefs and corresponding policies used by the current test.
   std::vector<std::string> types_;
   std::vector<std::string> pref_names_;
   std::vector<std::string> policy_names_;
   ScopedVector<base::Value> default_values_;
   ScopedVector<base::Value> non_default_values_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PreferencesBrowserTest);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_OPTIONS_PREFERENCES_BROWSERTEST_H_