Move AudioDecoder and related stuff to the api/ directory

webrtc/api/BUILD.gn

Index: webrtc/api/BUILD.gn
diff --git a/webrtc/api/BUILD.gn b/webrtc/api/BUILD.gn
index 8c443cb4780bee69614f6f0d8e963e0ec39e1130..b854c74968a92a4923ebdbb30da17bd15f7ca030 100644
--- a/webrtc/api/BUILD.gn
+++ b/webrtc/api/BUILD.gn
@@ -29,8 +29,8 @@ rtc_source_set("call_api") {
     ":transport_api",
     "..:webrtc_common",
     "../base:rtc_base_approved",
-    "../modules/audio_coding:audio_decoder_factory_interface",
     "../modules/audio_coding:audio_encoder_interface",
+    "audio_codec:audio_decoder_factory_interface",

[the sun, 2017/02/02 21:02:28]

nit: is this the preferred order? I'd have guessed audio_codec: would come
before the ".." targets.

[kwiberg-webrtc, 2017/02/03 09:50:11]

"gn format" sorts them this way. (And the precommit check makes sure that you
have run it, so unlike with C++ code formatting, you don't even have the option
of ignoring the tool. I must say I kind of like that---as long as the tool is
good enough, consistency is more important than the ability to manually tweak
things to perfection.)

   ]
 }