Add UMA stats for open audio input device failure.

media/audio/audio_input_controller.cc

Index: media/audio/audio_input_controller.cc
diff --git a/media/audio/audio_input_controller.cc b/media/audio/audio_input_controller.cc
index 490c62b3c16df6794d1ff6d17d18147f9c759a2c..4b365b788ab20b259a92d6ff1135fa60b9166456 100644
--- a/media/audio/audio_input_controller.cc
+++ b/media/audio/audio_input_controller.cc
@@ -47,6 +47,26 @@ const int kPowerMonitorLogIntervalSeconds = 5;
 #endif
 }
 
+// Used to log the result of capture startup.
+// This was previously logged as a boolean with only the no callback and OK
+// options. The enum order is kept to ensure backwards compatibility.
+// Elements in this enum should not be deleted or rearranged; the only
+// permitted operation is to add new elements before NUM_STREAM_OPEN_RESULT.

[Ilya Sherman, 2014/08/12 17:30:48]

nit: Please update the name "NUM_STREAM_OPEN_RESULT" to
"CAPTURE_STARTUP_RESULT_MAX".

[Henrik Grunell, 2014/08/13 12:31:30]

Done.

+enum CaptureStartupResult {
+  CAPTURE_STARTUP_NO_DATA_CALLBACK = 0,
+  CAPTURE_STARTUP_OK = 1,
+  CAPTURE_STARTUP_CREATE_STREAM_FAILED = 2,
+  CAPTURE_STARTUP_OPEN_STREAM_FAILED = 3,
+  CAPTURE_STARTUP_RESULT_MAX = CAPTURE_STARTUP_OPEN_STREAM_FAILED

[Ilya Sherman, 2014/08/12 17:30:48]

Optional nit: It's a little cleaner, IMO, to have this enum member be
CAPTURE_STARTUP_RESULT_COUNT, and have that be equal to 4.  That way you can
avoid the "+ 1" below; and also anyone adding values to this enum doesn't need
to remember to update this line as well.  For that second reason, I'd also omit
the explicit value assignments for all of the enum members -- the compiler is
better at assigning values in a linear sequence than humans are.

[Henrik Grunell, 2014/08/13 12:31:30]

The presubmit check actually complained about that, it had to be done this way.
It seems it could be specific for //media.
I think it's easier to see the match with the enum in histograms.xml when
written explicitly.

+};
+
+void LogStreamOpenResult(CaptureStartupResult result) {
+  UMA_HISTOGRAM_ENUMERATION("Media.AudioInputControllerCaptureStartupSuccess",
+                            result,
+                            CAPTURE_STARTUP_RESULT_MAX + 1);
+
+}
+
 namespace media {
 
 // static
@@ -157,8 +177,9 @@ scoped_refptr<AudioInputController> AudioInputController::CreateForStream(
   // mirroring use case only.
   if (!controller->task_runner_->PostTask(
           FROM_HERE,
-          base::Bind(&AudioInputController::DoCreateForStream, controller,
-                     stream, false))) {
+          base::Bind(&AudioInputController::DoCreateForStream,
+                     controller,
+                     stream))) {
     controller = NULL;
   }
 
@@ -209,12 +230,11 @@ void AudioInputController::DoCreate(AudioManager* audio_manager,
   // platform audio input requires the |no_data_timer_| be used to auto-detect
   // errors.  In reality, probably only Windows needs to be treated as
   // unreliable here.
-  DoCreateForStream(audio_manager->MakeAudioInputStream(params, device_id),
-                    true);
+  DoCreateForStream(audio_manager->MakeAudioInputStream(params, device_id));
 }
 
 void AudioInputController::DoCreateForStream(
-    AudioInputStream* stream_to_control, bool enable_nodata_timer) {
+    AudioInputStream* stream_to_control) {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   DCHECK(!stream_);
@@ -223,6 +243,7 @@ void AudioInputController::DoCreateForStream(
   if (!stream_) {
     if (handler_)
       handler_->OnError(this, STREAM_CREATE_ERROR);
+    LogStreamOpenResult(CAPTURE_STARTUP_CREATE_STREAM_FAILED);
     return;
   }
 
@@ -231,29 +252,24 @@ void AudioInputController::DoCreateForStream(
     stream_ = NULL;
     if (handler_)
       handler_->OnError(this, STREAM_OPEN_ERROR);
+    LogStreamOpenResult(CAPTURE_STARTUP_OPEN_STREAM_FAILED);
     return;
   }
 
   DCHECK(!no_data_timer_.get());
 
+  // Create the data timer which will call FirstCheckForNoData(). The timer
+  // is started in DoRecord() and restarted in each DoCheckForNoData()
+  // callback.
   // The timer is enabled for logging purposes. The NO_DATA_ERROR triggered
   // from the timer must be ignored by the EventHandler.
   // TODO(henrika): remove usage of timer when it has been verified on Canary
   // that we are safe doing so. Goal is to get rid of |no_data_timer_| and
   // everything that is tied to it. crbug.com/357569.
-  enable_nodata_timer = true;
-
-  if (enable_nodata_timer) {
-    // Create the data timer which will call FirstCheckForNoData(). The timer
-    // is started in DoRecord() and restarted in each DoCheckForNoData()
-    // callback.
-    no_data_timer_.reset(new base::Timer(
-        FROM_HERE, base::TimeDelta::FromSeconds(kTimerInitialIntervalSeconds),
-        base::Bind(&AudioInputController::FirstCheckForNoData,
-                   base::Unretained(this)), false));
-  } else {
-    DVLOG(1) << "Disabled: timer check for no data.";
-  }
+  no_data_timer_.reset(new base::Timer(
+      FROM_HERE, base::TimeDelta::FromSeconds(kTimerInitialIntervalSeconds),
+      base::Bind(&AudioInputController::FirstCheckForNoData,
+                 base::Unretained(this)), false));
 
   state_ = CREATED;
   if (handler_)
@@ -352,8 +368,9 @@ void AudioInputController::DoSetAutomaticGainControl(bool enabled) {
 
 void AudioInputController::FirstCheckForNoData() {
   DCHECK(task_runner_->BelongsToCurrentThread());
-  UMA_HISTOGRAM_BOOLEAN("Media.AudioInputControllerCaptureStartupSuccess",
-                        GetDataIsActive());
+  LogStreamOpenResult(GetDataIsActive() ?
+                      CAPTURE_STARTUP_OK :
+                      CAPTURE_STARTUP_NO_DATA_CALLBACK);
   DoCheckForNoData();
 }