Introduce VideoConfig/AudioConfig class for CMA backend

chromecast/media/media.gyp

Index: chromecast/media/media.gyp
diff --git a/chromecast/media/media.gyp b/chromecast/media/media.gyp
index 805f9e8ea3dc230cb309735f42863fd867553dc1..7604290691f3182e17e9efde0e14a58fa12b6f02 100644
--- a/chromecast/media/media.gyp
+++ b/chromecast/media/media.gyp
@@ -81,8 +81,14 @@
         'cma/base/decoder_buffer_adapter.h',
         'cma/base/decoder_buffer_base.cc',
         'cma/base/decoder_buffer_base.h',
+        'cma/base/decoder_config_adapter.cc',
+        'cma/base/decoder_config_adapter.h',
         'cma/base/media_task_runner.cc',
         'cma/base/media_task_runner.h',
+        'cma/public/audio_config.cc',
+        'cma/public/audio_config.h',
+        'cma/public/video_config.cc',
+        'cma/public/video_config.h',
       ],
     },
     {