Don't use base::Unretained in AudioDecodeScheduler.

remoting/client/audio_decode_scheduler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/client/audio_decode_scheduler.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "remoting/client/audio_player.h"
 #include "remoting/codec/audio_decoder.h"
 #include "remoting/proto/audio.pb.h"
 
 namespace remoting {
 
-AudioDecodeScheduler::AudioDecodeScheduler(
+class AudioDecodeScheduler::Core : public base::RefCountedThreadSafe<Core> {
+ public:
+  Core(scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+       scoped_refptr<base::SingleThreadTaskRunner> audio_decode_task_runner,
+       scoped_ptr<AudioPlayer> audio_player);
+
+  void Initialize(const protocol::SessionConfig& config);
+  void ProcessAudioPacket(scoped_ptr<AudioPacket> packet,
+                          const base::Closure& done);
+
+  // Called by AudioDecodeScheduler when it is destroyed.
+  void Detach();
+
+ private:
+  friend class base::RefCountedThreadSafe<Core>;
+
+  virtual ~Core();
+
+  // Called on the audio decoder thread.
+  void DecodePacket(scoped_ptr<AudioPacket> packet, const base::Closure& done);
+
+  // Called on the main thread.
+  void ProcessDecodedPacket(scoped_ptr<AudioPacket> packet,
+                            const base::Closure& done);
+
+  scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> audio_decode_task_runner_;
+  scoped_ptr<AudioDecoder> decoder_;
+  scoped_ptr<AudioPlayer> audio_player_;
+
+  DISALLOW_COPY_AND_ASSIGN(Core);
+};
+
+AudioDecodeScheduler::Core::Core(
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> audio_decode_task_runner,
     scoped_ptr<AudioPlayer> audio_player)
     : main_task_runner_(main_task_runner),
       audio_decode_task_runner_(audio_decode_task_runner),
       audio_player_(audio_player.Pass()) {
 }
 
-AudioDecodeScheduler::~AudioDecodeScheduler() {
+AudioDecodeScheduler::Core::~Core() {
 }
 
-void AudioDecodeScheduler::Initialize(const protocol::SessionConfig& config) {
+void AudioDecodeScheduler::Core::Initialize(
+    const protocol::SessionConfig& config) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   decoder_.reset(AudioDecoder::CreateAudioDecoder(config).release());
 }
 
-void AudioDecodeScheduler::ProcessAudioPacket(scoped_ptr<AudioPacket> packet,
-                                              const base::Closure& done) {
+void AudioDecodeScheduler::Core::ProcessAudioPacket(
+    scoped_ptr<AudioPacket> packet,
+    const base::Closure& done) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   audio_decode_task_runner_->PostTask(FROM_HERE, base::Bind(
-      &AudioDecodeScheduler::DecodePacket, base::Unretained(this),
+      &AudioDecodeScheduler::Core::DecodePacket, this,
       base::Passed(&packet), done));
 }
 
-void AudioDecodeScheduler::DecodePacket(scoped_ptr<AudioPacket> packet,
-                                        const base::Closure& done) {
+void AudioDecodeScheduler::Core::Detach() {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  audio_player_.reset();
+}
+
+void AudioDecodeScheduler::Core::DecodePacket(
+    scoped_ptr<AudioPacket> packet,
+    const base::Closure& done) {
   DCHECK(audio_decode_task_runner_->BelongsToCurrentThread());
   scoped_ptr<AudioPacket> decoded_packet = decoder_->Decode(packet.Pass());
 
   main_task_runner_->PostTask(FROM_HERE, base::Bind(
-      &AudioDecodeScheduler::ProcessDecodedPacket, base::Unretained(this),
+      &AudioDecodeScheduler::Core::ProcessDecodedPacket, this,
       base::Passed(decoded_packet.Pass()), done));
 }
 
-void AudioDecodeScheduler::ProcessDecodedPacket(scoped_ptr<AudioPacket> packet,
-                                                const base::Closure& done) {
+void AudioDecodeScheduler::Core::ProcessDecodedPacket(
+    scoped_ptr<AudioPacket> packet,
+    const base::Closure& done) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   // Only process |packet| if it is non-NULL.
-  if (packet.get())
+  if (packet.get() && audio_player_.get())
     audio_player_->ProcessAudioPacket(packet.Pass());
   done.Run();
 }
 
+AudioDecodeScheduler::AudioDecodeScheduler(
+    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> audio_decode_task_runner,
+    scoped_ptr<AudioPlayer> audio_player)
+    : core_(new Core(main_task_runner, audio_decode_task_runner,
+                     audio_player.Pass())) {
+}
+
+AudioDecodeScheduler::~AudioDecodeScheduler() {
+  core_->Detach();
+}
+
+void AudioDecodeScheduler::Initialize(const protocol::SessionConfig& config) {
+  core_->Initialize(config);
+}
+
+void AudioDecodeScheduler::ProcessAudioPacket(scoped_ptr<AudioPacket> packet,
+                                              const base::Closure& done) {
+  core_->ProcessAudioPacket(packet.Pass(), done);
+}
+
 }  // namespace remoting