Make AudioFrameType an enum class, and move to audio_coding_module_typedefs.h

Bug: webrtc:5876
Change-Id: I0c92f9410fcf0832bfa321229b3437134255dba6
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/128085
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27190}
diff --git a/common_types.h b/common_types.h
index 2dc1783..da48153 100644
--- a/common_types.h
+++ b/common_types.h
@@ -16,6 +16,9 @@
 
 // TODO(bugs.webrtc.org/7660): Delete include once downstream code is updated.
 #include "api/video/video_codec_type.h"
+// TODO(bugs.webrtc.org/5876): For AudioFrameType. Delete when downstream code
+// is updated.
+#include "modules/audio_coding/include/audio_coding_module_typedefs.h"
 
 #if defined(_MSC_VER)
 // Disable "new behavior: elements of array will be default initialized"
@@ -38,7 +41,6 @@
 // Can't use RTC_DEPRECATED until Chromium is updated.
 typedef FrameTypeDeprecated FrameType;
 
-using AudioFrameType = FrameTypeDeprecated;
 using VideoFrameType = FrameTypeDeprecated;
 
 // Statistics for RTCP packet types.