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

media/audio/win/audio_low_latency_output_win_unittest.cc

Index: media/audio/win/audio_low_latency_output_win_unittest.cc
===================================================================
--- media/audio/win/audio_low_latency_output_win_unittest.cc	(revision 155437)
+++ media/audio/win/audio_low_latency_output_win_unittest.cc	(working copy)
@@ -66,6 +66,9 @@
  public:
   MOCK_METHOD2(OnMoreData, int(AudioBus* audio_bus,
                                AudioBuffersState buffers_state));
+  MOCK_METHOD3(OnMoreIOData, int(AudioBus* source,
+                                 AudioBus* dest,
+                                 AudioBuffersState buffers_state));
   MOCK_METHOD2(OnError, void(AudioOutputStream* stream, int code));
 };
 
@@ -137,6 +140,13 @@
     return frames;
   }
 
+  virtual int OnMoreIOData(AudioBus* source,
+                           AudioBus* dest,
+                           AudioBuffersState buffers_state) OVERRIDE {
+    NOTREACHED();
+    return 0;
+  }
+
   virtual void OnError(AudioOutputStream* stream, int code) {}
 
   int file_size() { return file_->GetDataSize(); }