RefCounted types should not have public destructors, base/ edition

base/supports_user_data.h

Index: base/supports_user_data.h
diff --git a/base/supports_user_data.h b/base/supports_user_data.h
index d1c6c9a899eec6af4c0c2f3fba3dbad4db6b90e8..17899dd9c7893fe4929424bbb841e05b02e71a18 100644
--- a/base/supports_user_data.h
+++ b/base/supports_user_data.h
@@ -18,7 +18,6 @@ namespace base {
 class BASE_EXPORT SupportsUserData {
  public:
   SupportsUserData();
-  virtual ~SupportsUserData();
 
   // Derive from this class and add your own data members to associate extra
   // information with this object. Use GetUserData(key) and SetUserData()
@@ -34,6 +33,9 @@ class BASE_EXPORT SupportsUserData {
   Data* GetUserData(const void* key) const;
   void SetUserData(const void* key, Data* data);
 
+ protected:
+  virtual ~SupportsUserData();
+
  private:
   typedef std::map<const void*, linked_ptr<Data> > DataMap;