Audio output debug recording.

content/browser/renderer_host/media/audio_debug_file_writer.h

Index: content/browser/renderer_host/media/audio_debug_file_writer.h
diff --git a/content/browser/renderer_host/media/audio_debug_file_writer.h b/content/browser/renderer_host/media/audio_debug_file_writer.h
index 1ef10f186b18553f73abb4704db74359396bf592..07a2e81d41daae7be6e4281b098c65714610de6d 100644
--- a/content/browser/renderer_host/media/audio_debug_file_writer.h
+++ b/content/browser/renderer_host/media/audio_debug_file_writer.h
@@ -25,18 +25,25 @@ class AudioBus;
 
 namespace content {
 
-// Writes audio input data used for debugging purposes. All operations are
-// non-blocking.
+// Writes audio data to a 16 bit PCM WAVE file used for debugging purposes. All
+// operations are non-blocking.
 class CONTENT_EXPORT AudioDebugFileWriter
     : public NON_EXPORTED_BASE(media::AudioFileWriter) {
  public:
   explicit AudioDebugFileWriter(const media::AudioParameters& params);
   ~AudioDebugFileWriter() override;
 
+  // Number of channels and sample rate are used from |params|, the other
+  // parameters are ignored. The number of channels in the data passed to
+  // Write() must match |params|.
+  static std::unique_ptr<media::AudioFileWriter> Create(
+      const media::AudioParameters& params);
+
   void Start(const base::FilePath& file) override;
   void Stop() override;
   void Write(std::unique_ptr<media::AudioBus> data) override;
   bool WillWrite() override;
+  const base::FilePath::CharType* GetFileNameExtension() override;
 
  private:
   class AudioFileWriter;