RefCounted types should not have public destructors, base/ edition

base/threading/platform_thread.h

Index: base/threading/platform_thread.h
diff --git a/base/threading/platform_thread.h b/base/threading/platform_thread.h
index fc64f78967cc3660d49b96ae7f81aa2250423fea..de552c816a6a631133278c220f4e995a9c3675a3 100644
--- a/base/threading/platform_thread.h
+++ b/base/threading/platform_thread.h
@@ -54,8 +54,10 @@ class BASE_EXPORT PlatformThread {
   // ThreadMain method will be called on the newly created thread.
   class BASE_EXPORT Delegate {
    public:
-    virtual ~Delegate() {}
     virtual void ThreadMain() = 0;
+
+   protected:
+    virtual ~Delegate() {}
   };
 
   // Gets the current thread id, which may be useful for logging purposes.