Stop source and fire MediaStreamTrack ended event if missing audio input callbacks are detected.

media/audio/audio_input_device.h

Index: media/audio/audio_input_device.h
diff --git a/media/audio/audio_input_device.h b/media/audio/audio_input_device.h
index b62445701f033a6c4ab2ba9fd305c15ca7fbecf6..a633d4c30ccd439ad9edf455bd9525ed5414ee8e 100644
--- a/media/audio/audio_input_device.h
+++ b/media/audio/audio_input_device.h
@@ -59,6 +59,8 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/shared_memory.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
 #include "media/audio/audio_device_thread.h"
 #include "media/audio/audio_input_ipc.h"
 #include "media/audio/scoped_task_runner_observer.h"
@@ -128,6 +130,18 @@ class MEDIA_EXPORT AudioInputDevice
   // If the IO loop dies before we do, we shut down the audio thread from here.
   void WillDestroyCurrentMessageLoop() override;
 
+  // Checks if we have gotten callbacks within a certain time period. If no
+  // callbacks have been received, we report a capture error to the capture
+  // callback. Must be called on IO thread.
+  void CheckIfInputStreamIsAlive();
+
+  // Sets the last callback time |last_callback_time_|.
+  // SetLastCallbackTime() is called by AudioInputDevice::AudioThreadCallback on
+  // the audio thread and posts a task to SetLastCallbackTimeOnIOThread() which
+  // sets the variable.
+  void SetLastCallbackTime(base::TimeTicks last_callback_time);
+  void SetLastCallbackTimeOnIOThread(base::TimeTicks last_callback_time);
+
   AudioParameters audio_parameters_;
 
   CaptureCallback* callback_;
@@ -166,6 +180,13 @@ class MEDIA_EXPORT AudioInputDevice
   // callback via Start(). See http://crbug.com/151051 for details.
   bool stopping_hack_;
 
+  // Mechanism for detecting if we don't get callbacks when started.
+  // |check_alive_timer_| runs the check regularly.
+  // |last_callback_time_| stores the time for the last callback.
+  // Both must only be accessed on the IO thread.
+  base::RepeatingTimer check_alive_timer_;
+  base::TimeTicks last_callback_time_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(AudioInputDevice);
 };