Exposes a shlib interface for media/audio path.

chromecast/media/base/cast_media_default.cc

Index: chromecast/media/base/cast_media_default.cc
diff --git a/chromecast/media/base/cast_media_default.cc b/chromecast/media/base/cast_media_default.cc
index 0c177126ad6b3c9679001e20d3692bac941821b8..de590fa771f0eadca468970cea56f88d5e2e14ba 100644
--- a/chromecast/media/base/cast_media_default.cc
+++ b/chromecast/media/base/cast_media_default.cc
@@ -4,6 +4,7 @@
 
 #include "chromecast/public/cast_media_shlib.h"
 #include "chromecast/public/graphics_types.h"
+#include "chromecast/public/media/cast_audio_output_device.h"
 #include "chromecast/public/video_plane.h"
 
 namespace chromecast {
@@ -25,7 +26,45 @@ class DefaultVideoPlane : public VideoPlane {
   void OnScreenResolutionChanged(const Size& screen_res) override {}
 };
 
+class DefaultCastAudioOutputDevice : public CastAudioOutputDevice {
+ public:
+  DefaultCastAudioOutputDevice() {}
+  ~DefaultCastAudioOutputDevice() override {}
+
+  int GetMaximumOutputStreamsAllowed() const override { return 0; }
+
+  AudioParameters GetPreferredOutputStreamParameters(
+      const AudioParameters& suggested) const override {
+    return AudioParameters();
+  }
+
+  CastAudioOutputStream* MakeOutputStream(const AudioParameters& params,
+                                          TaskRunner* task_runner) override {
+    return nullptr;  // No streams allowed, always return nullptr
+  }
+};
+
+class DefaultCastAudioOutputStream : public CastAudioOutputStream {
+ public:
+  explicit DefaultCastAudioOutputStream(const AudioParameters& params)
+      : params_(params) {}
+  ~DefaultCastAudioOutputStream() override {}
+
+  // CastAudioOutputStream implementation:
+  const AudioParameters GetParameters() const override { return params_; }
+  bool Open() override { return false; }
+  void Start(AudioSourceCallback* callback) override {}
+  void Stop() override {}
+  void SetVolume(double volume) override {}
+  double GetVolume() override { return 0.0; }
+  void Close() override {}
+
+ private:
+  AudioParameters params_;
+};
+
 DefaultVideoPlane* g_video_plane = nullptr;
+DefaultCastAudioOutputDevice* g_audio_output_device = nullptr;
 
 }  // namespace
 
@@ -36,11 +75,22 @@ void CastMediaShlib::Initialize(const std::vector<std::string>& argv) {
 void CastMediaShlib::Finalize() {
   delete g_video_plane;
   g_video_plane = nullptr;
+
+  if (g_audio_output_device) {
+    delete g_audio_output_device;
+    g_audio_output_device = nullptr;
+  }
 }
 
 VideoPlane* CastMediaShlib::GetVideoPlane() {
   return g_video_plane;
 }
 
+CastAudioOutputDevice* CastMediaShlib::GetAudioOutputDevice() {
+  if (!g_audio_output_device)
+    g_audio_output_device = new DefaultCastAudioOutputDevice();
+  return g_audio_output_device;
+}
+
 }  // namespace media
 }  // namespace chromecast