AudioOutputDevice authorization timeout UMA histograms

media/audio/audio_output_device.h

Index: media/audio/audio_output_device.h
diff --git a/media/audio/audio_output_device.h b/media/audio/audio_output_device.h
index 945e77b638f49cf1019ee7bd3bfdcfb4c2091fe2..97f4eb3c5c0c09aa3c9d6a6161b9c3ccc9074adf 100644
--- a/media/audio/audio_output_device.h
+++ b/media/audio/audio_output_device.h
@@ -69,6 +69,7 @@
 #include "base/macros.h"
 #include "base/memory/shared_memory.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/time/time.h"
 #include "media/audio/audio_device_thread.h"
 #include "media/audio/audio_output_ipc.h"
 #include "media/audio/scoped_task_runner_observer.h"
@@ -78,6 +79,7 @@
 #include "media/base/output_device_info.h"
 
 namespace base {
+class ElapsedTimer;
 class OneShotTimer;
 }
 
@@ -217,6 +219,9 @@ class MEDIA_EXPORT AudioOutputDevice
   const base::TimeDelta auth_timeout_;
   std::unique_ptr<base::OneShotTimer> auth_timeout_action_;
 
+  // Tracks how long it takes to get authorization response.
+  std::unique_ptr<base::ElapsedTimer> auth_timer_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioOutputDevice);
 };