[Chromecast] Move CastAudioDecoder out to chromecast/media/cma/decoder

chromecast/media/base/BUILD.gn

Index: chromecast/media/base/BUILD.gn
diff --git a/chromecast/media/base/BUILD.gn b/chromecast/media/base/BUILD.gn
index 7d02a3a335f87e1190db87f2f9cedfa19c847a72..f0d85fe3aa8e69f4c5d2a006c08e577fd7112aa2 100644
--- a/chromecast/media/base/BUILD.gn
+++ b/chromecast/media/base/BUILD.gn
@@ -41,6 +41,35 @@ source_set("key_systems") {
   ]
 }
 
+source_set("decoder_buffer") {
+  sources = [
+    "decoder_buffer_base.h",
+  ]
+
+  public_deps = [
+    "//chromecast/public/media",
+  ]
+
+  deps = [
+    "//base",
+  ]
+}
+
+source_set("decoder") {
+  sources = [
+    "cast_audio_decoder.h",
+    "cast_audio_decoder_android.cc",
+    "cast_audio_decoder_linux.cc",
+  ]
+
+  deps = [
+    ":decoder_buffer",
+    "//base",
+    "//media",
+    "//media:shared_memory_support",
+  ]
+}
+
 # TODO(slan): See if the dependency on //media can be broken.
 source_set("base") {
   sources = [