Remove a scoped_refptr<>::swap overload

media/filters/ffmpeg_audio_decoder.cc

Index: media/filters/ffmpeg_audio_decoder.cc
diff --git a/media/filters/ffmpeg_audio_decoder.cc b/media/filters/ffmpeg_audio_decoder.cc
index e3560ff1b8bcf9d359f2a7c0ab06147b8e6b4e3f..06233eaa7d141c033ac0c80a7574defee61d04ba 100644
--- a/media/filters/ffmpeg_audio_decoder.cc
+++ b/media/filters/ffmpeg_audio_decoder.cc
@@ -45,8 +45,8 @@ static inline int DetermineChannels(AVFrame* frame) {
 // Called by FFmpeg's allocation routine to free a buffer. |opaque| is the
 // AudioBuffer allocated, so unref it.
 static void ReleaseAudioBufferImpl(void* opaque, uint8_t* data) {
-  scoped_refptr<AudioBuffer> buffer;
-  buffer.swap(reinterpret_cast<AudioBuffer**>(&opaque));
+  if (opaque)
+    static_cast<AudioBuffer*>(opaque)->Release();
 }
 
 // Called by FFmpeg's allocation routine to allocate a buffer. Uses
@@ -124,8 +124,8 @@ static int GetAudioBuffer(struct AVCodecContext* s, AVFrame* frame, int flags) {
 
   // Now create an AVBufferRef for the data just allocated. It will own the
   // reference to the AudioBuffer object.
-  void* opaque = NULL;
-  buffer.swap(reinterpret_cast<AudioBuffer**>(&opaque));
+  AudioBuffer* opaque = buffer.get();
+  opaque->AddRef();

[xhwang, 2017/03/03 18:36:08]

This is hard to read (not saying it's worse than before :) )...

Is there any plan to improve the API on this kind of use case?

[dcheng, 2017/03/03 18:45:19]

Eh... this seems Good Enough (tm) for the use case where we have to leak a ref
to C. I'm not really sure what else we could use here: I guess we could have
LeakRef() on scoped_refptr, but if we don't need it, it might be best to avoid.

   frame->buf[0] = av_buffer_create(
       frame->data[0], buffer_size_in_bytes, ReleaseAudioBufferImpl, opaque, 0);
   return 0;