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

2 files changed, 10 insertions, 4 deletions

diff --git a/media/video/capture/video_capture.h b/media/video/capture/video_capture.h
index b825dff..d0aef98 100644
--- a/media/video/capture/video_capture.h
+++ b/media/video/capture/video_capture.h
@@ -44,7 +44,7 @@ class MEDIA_EXPORT VideoCapture {
 
   // TODO(wjia): add error codes.
   // Callbacks provided by client for notification of events.
-  class EventHandler {
+  class MEDIA_EXPORT EventHandler {
    public:
     // Notify client that video capture has been started.
     virtual void OnStarted(VideoCapture* capture) = 0;
@@ -70,10 +70,12 @@ class MEDIA_EXPORT VideoCapture {
     virtual void OnDeviceInfoReceived(
         VideoCapture* capture,
         const VideoCaptureParams& device_info) = 0;
+
+   protected:
+    virtual ~EventHandler() {}
   };
 
   VideoCapture() {}
-  virtual ~VideoCapture() {}
 
   // Request video capture to start capturing with |capability|.
   // Also register |handler| with video capture for event handling.
@@ -93,6 +95,9 @@ class MEDIA_EXPORT VideoCapture {
   virtual int CaptureHeight() = 0;
   virtual int CaptureFrameRate() = 0;
 
+ protected:
+  virtual ~VideoCapture() {}
+
  private:
   DISALLOW_COPY_AND_ASSIGN(VideoCapture);
 };
diff --git a/media/video/video_decode_accelerator.h b/media/video/video_decode_accelerator.h
index c04d8dc..83d0b95 100644
--- a/media/video/video_decode_accelerator.h
+++ b/media/video/video_decode_accelerator.h
@@ -46,8 +46,6 @@ class MEDIA_EXPORT VideoDecodeAccelerator
   // implements.
   class MEDIA_EXPORT Client {
    public:
-    virtual ~Client() {}
-
     // Callback to notify client that decoder has been initialized.
     virtual void NotifyInitializeDone() = 0;
 
@@ -74,6 +72,9 @@ class MEDIA_EXPORT VideoDecodeAccelerator
 
     // Callback to notify about decoding errors.
     virtual void NotifyError(Error error) = 0;
+
+   protected:
+    virtual ~Client() {}
   };
 
   // Video decoder functions.