RefCounted types should not have public destructors, chrome/browser/ part 6

chrome/browser/memory_purger.cc

Index: chrome/browser/memory_purger.cc
diff --git a/chrome/browser/memory_purger.cc b/chrome/browser/memory_purger.cc
index 7c2fd9e0154d4cfb13048e04382ed810244f7409..6e2c14ffc0dc1100725212f84ee3b26feba4083e 100644
--- a/chrome/browser/memory_purger.cc
+++ b/chrome/browser/memory_purger.cc
@@ -46,9 +46,13 @@ class PurgeMemoryIOHelper
   void PurgeMemoryOnIOThread();
 
  private:
-  typedef scoped_refptr<net::URLRequestContextGetter> RequestContextGetter;
+  friend class base::RefCountedThreadSafe<PurgeMemoryIOHelper>;
+
+  virtual ~PurgeMemoryIOHelper() {}
 
+  typedef scoped_refptr<net::URLRequestContextGetter> RequestContextGetter;
   std::vector<RequestContextGetter> request_context_getters_;
+
   scoped_refptr<SafeBrowsingService> safe_browsing_service_;
 
   DISALLOW_COPY_AND_ASSIGN(PurgeMemoryIOHelper);