Audio output debug recording.

chrome/browser/media/webrtc/audio_debug_recordings_handler.cc

Index: chrome/browser/media/webrtc/audio_debug_recordings_handler.cc
diff --git a/chrome/browser/media/webrtc/audio_debug_recordings_handler.cc b/chrome/browser/media/webrtc/audio_debug_recordings_handler.cc
index cd712ad7f6340b2de732535308bbbc4bc8f1377f..cc25172e7efec48bc4530be80893eac843eeef3b 100644
--- a/chrome/browser/media/webrtc/audio_debug_recordings_handler.cc
+++ b/chrome/browser/media/webrtc/audio_debug_recordings_handler.cc
@@ -17,6 +17,7 @@
 #include "chrome/common/chrome_switches.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
+#include "media/audio/audio_manager.h"
 
 using content::BrowserThread;
 
@@ -106,6 +107,13 @@ void AudioDebugRecordingsHandler::DoStartAudioDebugRecordings(
       log_directory, ++current_audio_debug_recordings_id_);
   host->EnableAudioDebugRecordings(prefix_path);
 
+  // AudioManager is deleted on the audio thread, and the AudioManager outlives
+  // this object, so it's safe to post unretained.

[o1ka, 2017/01/31 11:00:11]

Add why media::AudioManager::Get() is safe (or better use a pointer instead)?

[Henrik Grunell, 2017/02/08 11:29:37]

Changed to a pointer injected.

+  media::AudioManager* audio_manager = media::AudioManager::Get();

[Max Morin, 2017/01/30 10:24:01]

The AudioManager::Get() pointer is nulled on the UI thread, before the
AudioManager is actually deleted. Are you sure you can't get null here? (The
lifetime of this object isn't obvious to me).

[Henrik Grunell, 2017/01/30 14:11:26]

I'll double check that tomorrow.

[Henrik Grunell, 2017/02/08 11:29:37]

This class lives on the UI thread, which is implicit. See the PostDelayedTask
below - it posts on the UI thread to run DoStopAudioDebugRecordings(), which
uses the class wide thread checker. I've changed to check the UI thread
explicitly in all functions instead which makes that clearer.

After doing that, I also changed to inject a pointer instead based on Olga's
comment above.

+  audio_manager->GetTaskRunner()->PostTask(
+      FROM_HERE, base::Bind(&media::AudioManager::EnableOutputDebugRecording,
+                            base::Unretained(audio_manager), prefix_path));
+
   if (delay.is_zero()) {
     const bool is_stopped = false, is_manual_stop = false;
     callback.Run(prefix_path.AsUTF8Unsafe(), is_stopped, is_manual_stop);
@@ -149,7 +157,15 @@ void AudioDebugRecordingsHandler::DoStopAudioDebugRecordings(
     return;
   }
 
+  // AudioManager is deleted on the audio thread, and the AudioManager outlives
+  // this object, so it's safe to post unretained.
+  media::AudioManager* audio_manager = media::AudioManager::Get();
+  audio_manager->GetTaskRunner()->PostTask(
+      FROM_HERE, base::Bind(&media::AudioManager::DisableOutputDebugRecording,
+                            base::Unretained(audio_manager)));
+
   host->DisableAudioDebugRecordings();
+
   is_audio_debug_recordings_in_progress_ = false;
   const bool is_stopped = true;
   callback.Run(prefix_path.AsUTF8Unsafe(), is_stopped, is_manual_stop);