Make DefaultDeleter for Video{De|En}codeAccelerator

media/video/video_decode_accelerator.h

Index: media/video/video_decode_accelerator.h
diff --git a/media/video/video_decode_accelerator.h b/media/video/video_decode_accelerator.h
index 950ac8d143e633b87aecfe666395ea1ee8174dad..7025a51cc82ae5db83b9befcc17fb0284005e5ff 100644
--- a/media/video/video_decode_accelerator.h
+++ b/media/video/video_decode_accelerator.h
@@ -20,8 +20,6 @@ namespace media {
 // implement the backend of PPB_VideoDecode_Dev.
 class MEDIA_EXPORT VideoDecodeAccelerator {
  public:
-  virtual ~VideoDecodeAccelerator();
-
   // Enumeration of potential errors generated by the API.
   // Note: Keep these in sync with PP_VideoDecodeError_Dev. Also do not
   // rearrange, reuse or remove values as they are used for gathering UMA
@@ -133,8 +131,28 @@ class MEDIA_EXPORT VideoDecodeAccelerator {
   // no more callbacks will be made on the client.  Deletes |this|
   // unconditionally, so make sure to drop all pointers to it!
   virtual void Destroy() = 0;
+
+ protected:
+  // Do not delete directly; use Destroy() or own it with a scoped_ptr, which
+  // will Destroy() it properly by default.
+  virtual ~VideoDecodeAccelerator();
 };
 
 }  // namespace media
 
+namespace base {
+
+template <class T>
+struct DefaultDeleter;
+
+// Specialize DefaultDeleter so that scoped_ptr<VideoDecodeAccelerator> always
+// uses "Destroy()" instead of trying to use the destructor.
+template <>
+struct MEDIA_EXPORT DefaultDeleter<media::VideoDecodeAccelerator> {
+ public:
+  void operator()(void* video_decode_accelerator) const;
+};
+
+}  // namespace base
+
 #endif  // MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_