Improve logging related to start/stop and failure of audio input streams in Chrome

media/audio/audio_manager_base.cc

Index: media/audio/audio_manager_base.cc
diff --git a/media/audio/audio_manager_base.cc b/media/audio/audio_manager_base.cc
index 3b36b106fa681659dc78b6e894a1965a7d93cae4..4a6e4ac9231007632eb2c833c773a46f78841eb2 100644
--- a/media/audio/audio_manager_base.cc
+++ b/media/audio/audio_manager_base.cc
@@ -8,6 +8,7 @@
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/stringprintf.h"
 #include "build/build_config.h"
 #include "media/audio/audio_output_dispatcher_impl.h"
 #include "media/audio/audio_output_proxy.h"
@@ -80,6 +81,7 @@ AudioManagerBase::AudioManagerBase(AudioLogFactory* audio_log_factory)
       // block the UI thread when swapping devices.
       output_listeners_(
           ObserverList<AudioDeviceListener>::NOTIFY_EXISTING_ONLY),
+      state_listeners_(ObserverList<StateChangeListener>::NOTIFY_EXISTING_ONLY),
       audio_thread_("AudioThread"),
       audio_log_factory_(audio_log_factory) {
 #if defined(OS_WIN)
@@ -185,6 +187,10 @@ AudioInputStream* AudioManagerBase::MakeAudioInputStream(
   // this method on the audio thread, then uncomment the following:
   // DCHECK(task_runner_->BelongsToCurrentThread());
 
+  std::string log_string = base::StringPrintf(
+      "MakeAudioInputStream(device_id=%s)", device_id.c_str());

[Henrik Grunell, 2014/08/22 16:14:43]

Is this id something that can identify someone?

[no longer working on chromium, 2014/08/25 08:20:05]

as I pointed out, we can't log the device_id due to privacy concern.

[henrika (OOO until Aug 14), 2014/08/25 12:47:45]

Removed.

But Shijing, we do log it at other places? Why is it not always a privacy
concern?

+  NotifyAllStateChangeListeners(log_string);
+
   if (!params.IsValid() || (params.channels() > kMaxInputChannels) ||
       device_id.empty()) {
     DLOG(ERROR) << "Audio parameters are invalid for device " << device_id;
@@ -216,6 +222,9 @@ AudioInputStream* AudioManagerBase::MakeAudioInputStream(
 
   if (stream) {
     ++num_input_streams_;
+    log_string = base::StringPrintf(
+        "MakeAudioInputStream => num_input_streams = %d", num_input_streams_);

[Henrik Grunell, 2014/08/22 16:14:43]

Do we need the above if we have this? What about the fail cases?

[henrika (OOO until Aug 14), 2014/08/25 12:47:45]

Thanks. Improved.

+    NotifyAllStateChangeListeners(log_string);
   }
 
   return stream;
@@ -315,6 +324,10 @@ void AudioManagerBase::ReleaseInputStream(AudioInputStream* stream) {
   DCHECK(stream);
   // TODO(xians) : Have a clearer destruction path for the AudioInputStream.
   --num_input_streams_;
+  std::string log_string = base::StringPrintf(
+      "ReleaseInputStream => num_input_streams = %d",
+      num_input_streams_);
+  NotifyAllStateChangeListeners(log_string);
   delete stream;
 }
 
@@ -358,6 +371,25 @@ void AudioManagerBase::NotifyAllOutputDeviceChangeListeners() {
   FOR_EACH_OBSERVER(AudioDeviceListener, output_listeners_, OnDeviceChange());
 }
 
+void AudioManagerBase::AddStateChangeListener(StateChangeListener* listener) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  state_listeners_.AddObserver(listener);
+}
+
+void AudioManagerBase::RemoveStateChangeListener(
+    StateChangeListener* listener) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  state_listeners_.RemoveObserver(listener);
+}
+
+void AudioManagerBase::NotifyAllStateChangeListeners(const std::string& msg) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  std::string log_string("AMB::");
+  log_string += msg;
+  FOR_EACH_OBSERVER(
+      StateChangeListener, state_listeners_, OnStateChange(log_string));
+}
+
 AudioParameters AudioManagerBase::GetDefaultOutputStreamParameters() {
   return GetPreferredOutputStreamParameters(GetDefaultOutputDeviceID(),
       AudioParameters());