Move media::AudioCodec to its own source file

media/base/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/config/linux/pkg_config.gni")
 import("//media/media_options.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 
 source_set("base") {
   # This is part of the media component.
   visibility = [ "//media" ]
   sources = [
     "audio_block_fifo.cc",
     "audio_block_fifo.h",
     "audio_buffer.cc",
     "audio_buffer.h",
     "audio_buffer_converter.cc",
     "audio_buffer_converter.h",
     "audio_buffer_queue.cc",
     "audio_buffer_queue.h",
     "audio_capturer_source.h",
+    "audio_codecs.cc",
+    "audio_codecs.h",
     "audio_converter.cc",
     "audio_converter.h",
     "audio_decoder.cc",
     "audio_decoder.h",
     "audio_decoder_config.cc",
     "audio_decoder_config.h",
     "audio_discard_helper.cc",
     "audio_discard_helper.h",
     "audio_fifo.cc",
     "audio_fifo.h",
@@ skipping 517 matching lines @@
 
 fuzzer_test("media_container_names_fuzzer") {
   sources = [
     "container_names_fuzzertest.cc",
   ]
   deps = [
     "//base",
     "//media",
   ]
 }