RefCounted types should not have public destructors, delegate cleanup

chrome/browser/policy/policy_service.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_POLICY_POLICY_SERVICE_H_
 #define CHROME_BROWSER_POLICY_POLICY_SERVICE_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 18 matching lines @@
 
 // The PolicyService merges policies from all available sources, taking into
 // account their priorities. Policy clients can retrieve policy for their domain
 // and register for notifications on policy updates.
 //
 // The PolicyService is available from BrowserProcess as a global singleton.
 class PolicyService {
  public:
   class Observer {
    public:
-    virtual ~Observer() {}
-
     // Invoked whenever policies for the |domain|, |component_id| namespace are
     // modified. This is only invoked for changes that happen after AddObserver
     // is called. |previous| contains the values of the policies before the
     // update, and |current| contains the current values.
     virtual void OnPolicyUpdated(PolicyDomain domain,
                                  const std::string& component_id,
                                  const PolicyMap& previous,
                                  const PolicyMap& current) = 0;
 
     // Invoked at most once, when the PolicyService becomes ready. If
     // IsInitializationComplete() is false, then this will be invoked once all
     // the policy providers are ready.
     virtual void OnPolicyServiceInitialized() {}
+
+   protected:
+    virtual ~Observer() {}
   };
 
   virtual ~PolicyService() {}
 
   virtual void AddObserver(PolicyDomain domain,
                            const std::string& component_id,
                            Observer* observer) = 0;
 
   virtual void RemoveObserver(PolicyDomain domain,
                               const std::string& component_id,
@@ skipping 56 matching lines @@
   PolicyDomain domain_;
   std::string component_id_;
   CallbackMap callback_map_;
 
   DISALLOW_COPY_AND_ASSIGN(PolicyChangeRegistrar);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_POLICY_SERVICE_H_