RefCounted types should not have public destructors, delegate cleanup

media/base/data_source.h

Index: media/base/data_source.h
diff --git a/media/base/data_source.h b/media/base/data_source.h
index a394a038853bb00b07495210c5c56c2712f732a2..23055fb75abfb5c98cda8c90b7c69243df6e0ac8 100644
--- a/media/base/data_source.h
+++ b/media/base/data_source.h
@@ -13,8 +13,6 @@ namespace media {
 
 class MEDIA_EXPORT DataSourceHost {
  public:
-  virtual ~DataSourceHost();
-
   // Set the total size of the media file.
   virtual void SetTotalBytes(int64 total_bytes) = 0;
 
@@ -24,6 +22,9 @@ class MEDIA_EXPORT DataSourceHost {
 
   // Sets the flag to indicate current network activity.
   virtual void SetNetworkActivity(bool is_downloading_data) = 0;
+
+ protected:
+  virtual ~DataSourceHost();
 };
 
 class MEDIA_EXPORT DataSource : public base::RefCountedThreadSafe<DataSource> {