Allow audio system to handle synchronized low-latency audio I/O

media/audio/audio_low_latency_input_output_unittest.cc

Index: media/audio/audio_low_latency_input_output_unittest.cc
===================================================================
--- media/audio/audio_low_latency_input_output_unittest.cc	(revision 155437)
+++ media/audio/audio_low_latency_input_output_unittest.cc	(working copy)
@@ -256,6 +256,13 @@
     return 0;
   }
 
+  virtual int OnMoreIOData(AudioBus* source,
+                           AudioBus* dest,
+                           AudioBuffersState buffers_state) OVERRIDE {
+    NOTREACHED();
+    return 0;
+  }
+
   virtual void OnError(AudioOutputStream* stream, int code) OVERRIDE {}
   virtual void WaitTillDataReady() OVERRIDE {}