Reland: Remove reference counting from media::VideoDecoder and friends.

media/filters/video_frame_stream.cc

Index: media/filters/video_frame_stream.cc
diff --git a/media/filters/video_frame_stream.cc b/media/filters/video_frame_stream.cc
index 72ee20df8723644a816ec22db8a4138edd4a94b7..93f2a0ea16d304a138a2963beb190c989ca4c513 100644
--- a/media/filters/video_frame_stream.cc
+++ b/media/filters/video_frame_stream.cc
@@ -19,10 +19,12 @@ namespace media {
 
 VideoFrameStream::VideoFrameStream(
     const scoped_refptr<base::MessageLoopProxy>& message_loop,
+    ScopedVector<VideoDecoder> decoders,
     const SetDecryptorReadyCB& set_decryptor_ready_cb)
     : message_loop_(message_loop),
       weak_factory_(this),
       state_(UNINITIALIZED),
+      decoders_(decoders.Pass()),
       set_decryptor_ready_cb_(set_decryptor_ready_cb) {
 }
 
@@ -31,7 +33,6 @@ VideoFrameStream::~VideoFrameStream() {
 }
 
 void VideoFrameStream::Initialize(const scoped_refptr<DemuxerStream>& stream,
-                                  const VideoDecoderList& decoders,
                                   const StatisticsCB& statistics_cb,
                                   const InitCB& init_cb) {
   DCHECK(message_loop_->BelongsToCurrentThread());
@@ -44,20 +45,18 @@ void VideoFrameStream::Initialize(const scoped_refptr<DemuxerStream>& stream,
   init_cb_ = init_cb;
   stream_ = stream;
 
-  scoped_ptr<VideoDecoderSelector> decoder_selector(
-      new VideoDecoderSelector(message_loop_,
-                               decoders,
-                               set_decryptor_ready_cb_));
+  // TODO(scherkus): Make |decoder_selector| a member variable after
+  // DemuxerStream is no longer refcounted. Today we're forced to do this
+  // because it creates a refcount loop between |this| and |decoder_selector|.
+  scoped_ptr<VideoDecoderSelector> decoder_selector(new VideoDecoderSelector(
+      message_loop_, decoders_.Pass(), set_decryptor_ready_cb_));
+  set_decryptor_ready_cb_.Reset();
 
-  // To avoid calling |decoder_selector| methods and passing ownership of
-  // |decoder_selector| in the same line.
   VideoDecoderSelector* decoder_selector_ptr = decoder_selector.get();
 
-  decoder_selector_ptr->SelectVideoDecoder(
-      this,
-      statistics_cb,
-      base::Bind(&VideoFrameStream::OnDecoderSelected, weak_this_,
-                 base::Passed(&decoder_selector)));
+  decoder_selector_ptr->SelectVideoDecoder(this, statistics_cb, base::Bind(
+      &VideoFrameStream::OnDecoderSelected, weak_this_,
+      base::Passed(&decoder_selector)));
 }
 
 void VideoFrameStream::ReadFrame(const VideoDecoder::ReadCB& read_cb) {
@@ -128,7 +127,7 @@ void VideoFrameStream::Stop(const base::Closure& closure) {
   // we don't need this here. See: http://crbug.com/173313
   stream_ = NULL;
   decrypting_demuxer_stream_ = NULL;
-  decoder_ = NULL;
+  decoder_.reset();
   message_loop_->PostTask(FROM_HERE, base::ResetAndReturn(&stop_cb_));
 }
 
@@ -165,7 +164,7 @@ void VideoFrameStream::EnableBitstreamConverter() {
 
 void VideoFrameStream::OnDecoderSelected(
     scoped_ptr<VideoDecoderSelector> decoder_selector,
-    const scoped_refptr<VideoDecoder>& selected_decoder,
+    scoped_ptr<VideoDecoder> selected_decoder,
     const scoped_refptr<DecryptingDemuxerStream>& decrypting_demuxer_stream) {
   DCHECK(message_loop_->BelongsToCurrentThread());
   DCHECK_EQ(state_, UNINITIALIZED);
@@ -175,7 +174,7 @@ void VideoFrameStream::OnDecoderSelected(
     state_ = UNINITIALIZED;
     base::ResetAndReturn(&init_cb_).Run(false, false);
   } else {
-    decoder_ = selected_decoder;
+    decoder_ = selected_decoder.Pass();
     decrypting_demuxer_stream_ = decrypting_demuxer_stream;
     state_ = NORMAL;
     base::ResetAndReturn(&init_cb_).Run(true, decoder_->HasAlpha());
@@ -239,7 +238,7 @@ void VideoFrameStream::OnDecoderStopped() {
   // we don't need this here. See: http://crbug.com/173313
   stream_ = NULL;
   decrypting_demuxer_stream_ = NULL;
-  decoder_ = NULL;
+  decoder_.reset();
   base::ResetAndReturn(&stop_cb_).Run();
 }