RefCounted types should not have public destructors, delegate cleanup

For Delegate/Observer-type classes that specify an
interface but do not have any particular lifetime
requirements, make their destructors protected. This is to
allow their interfaces to be implemented safely by
RefCounted types. With public destructors, it's possible to
do "scoped_ptr<Delegate> foo", and then assign a
RefCountedDelegateImpl, which would lead to a double free.

As none of these Delegates actually need public destructors
(ownership of the Delegate* is not transferred during a
function call / class constructor), mark the destructors
protected so that it becomes a compile warning to try to
delete them via the Delegate*.

BUG=123295
TEST=it compiles


Review URL: https://chromiumcodereview.appspot.com/10383262

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@144086 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 3 insertions, 2 deletions

diff --git a/ppapi/proxy/host_dispatcher.h b/ppapi/proxy/host_dispatcher.h
index 6c4dd2d..da64467 100644
--- a/ppapi/proxy/host_dispatcher.h
+++ b/ppapi/proxy/host_dispatcher.h
@@ -33,14 +33,15 @@ class PPAPI_PROXY_EXPORT HostDispatcher : public Dispatcher {
   // actually represents a stack of blocking messages.
   class SyncMessageStatusReceiver : public IPC::ChannelProxy::MessageFilter {
    public:
-    virtual ~SyncMessageStatusReceiver() {}
-
     // Notification that a sync message is about to be sent out.
     virtual void BeginBlockOnSyncMessage() = 0;
 
     // Notification that a sync message reply was received and the dispatcher
     // is no longer blocked on a sync message.
     virtual void EndBlockOnSyncMessage() = 0;
+
+   protected:
+    virtual ~SyncMessageStatusReceiver() {}
   };
 
   // Constructor for the renderer side. This will take a reference to the