Delete enum NetEqDecoder.

A trimmed down version is moved to legacy_encoded_audio_frame_unittest.cc
where it's used for test parameterization.

Bug: webrtc:10185
Change-Id: I9abda22f9806b831b6ca4b27d6bcc888285f50f2
Reviewed-on: https://webrtc-review.googlesource.com/c/116961
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26218}

modules/audio_coding/codecs/legacy_encoded_audio_frame_unittest.cc

@@ -10,12 +10,28 @@
 
 #include "modules/audio_coding/codecs/legacy_encoded_audio_frame.h"
 
-#include "modules/audio_coding/neteq/neteq_decoder_enum.h"
 #include "rtc_base/numerics/safe_conversions.h"
 #include "test/gtest.h"
 
 namespace webrtc {
 
+enum class NetEqDecoder {
+  kDecoderPCMu,
+  kDecoderPCMa,
+  kDecoderPCMu_2ch,
+  kDecoderPCMa_2ch,
+  kDecoderPCM16B,
+  kDecoderPCM16Bwb,
+  kDecoderPCM16Bswb32kHz,
+  kDecoderPCM16Bswb48kHz,
+  kDecoderPCM16B_2ch,
+  kDecoderPCM16Bwb_2ch,
+  kDecoderPCM16Bswb32kHz_2ch,
+  kDecoderPCM16Bswb48kHz_2ch,
+  kDecoderPCM16B_5ch,
+  kDecoderG722,
+};
+
 class SplitBySamplesTest : public ::testing::TestWithParam<NetEqDecoder> {
  protected:
   virtual void SetUp() {