Add a simple, safe gain PostProcessor.

chromecast/media/cma/backend/alsa/cast_audio_json.cc

Index: chromecast/media/cma/backend/alsa/cast_audio_json.cc
diff --git a/chromecast/media/cma/backend/alsa/cast_audio_json.cc b/chromecast/media/cma/backend/alsa/cast_audio_json.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bb1d36f67b635265dd0d773532a4aefa2ac81fe1
--- /dev/null
+++ b/chromecast/media/cma/backend/alsa/cast_audio_json.cc
@@ -0,0 +1,15 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chromecast/media/cma/backend/alsa/cast_audio_json.h"
+
+namespace chromecast {
+namespace media {
+
+std::string GetCastAudioJsonFilePath() {

[kmackay, 2017/06/30 17:59:38]

Why does this need to be a function instead of a constant?

[bshaya, 2017/07/06 21:04:44]

Done.

+  return "/etc/cast_audio.json";
+}
+
+}  // namespace media
+}  // namespace chromecast