Make an enum class out of NetEqDecoder, and hide the neteq_decoders_ table

webrtc/modules/audio_coding/neteq/payload_splitter.cc

Index: webrtc/modules/audio_coding/neteq/payload_splitter.cc
diff --git a/webrtc/modules/audio_coding/neteq/payload_splitter.cc b/webrtc/modules/audio_coding/neteq/payload_splitter.cc
index 2172eee1ec5219ea826a7c37398600973575bab5..8530718134160341fff8519042f7b35f87d28fc5 100644
--- a/webrtc/modules/audio_coding/neteq/payload_splitter.cc
+++ b/webrtc/modules/audio_coding/neteq/payload_splitter.cc
@@ -152,8 +152,8 @@ int PayloadSplitter::SplitFec(PacketList* packet_list,
     }
 
     switch (info->codec_type) {
-      case kDecoderOpus:
-      case kDecoderOpus_2ch: {
+      case NetEqDecoder::kDecoderOpus:
+      case NetEqDecoder::kDecoderOpus_2ch: {
         // The main payload of this packet should be decoded as a primary
         // payload, even if it comes as a secondary payload in a RED packet.
         packet->primary = true;
@@ -236,69 +236,69 @@ int PayloadSplitter::SplitAudio(PacketList* packet_list,
     }
     PacketList new_packets;
     switch (info->codec_type) {
-      case kDecoderPCMu:
-      case kDecoderPCMa: {
+      case NetEqDecoder::kDecoderPCMu:
+      case NetEqDecoder::kDecoderPCMa: {
         // 8 bytes per ms; 8 timestamps per ms.
         SplitBySamples(packet, 8, 8, &new_packets);
         break;
       }
-      case kDecoderPCMu_2ch:
-      case kDecoderPCMa_2ch: {
+      case NetEqDecoder::kDecoderPCMu_2ch:
+      case NetEqDecoder::kDecoderPCMa_2ch: {
         // 2 * 8 bytes per ms; 8 timestamps per ms.
         SplitBySamples(packet, 2 * 8, 8, &new_packets);
         break;
       }
-      case kDecoderG722: {
+      case NetEqDecoder::kDecoderG722: {
         // 8 bytes per ms; 16 timestamps per ms.
         SplitBySamples(packet, 8, 16, &new_packets);
         break;
       }
-      case kDecoderPCM16B: {
+      case NetEqDecoder::kDecoderPCM16B: {
         // 16 bytes per ms; 8 timestamps per ms.
         SplitBySamples(packet, 16, 8, &new_packets);
         break;
       }
-      case kDecoderPCM16Bwb: {
+      case NetEqDecoder::kDecoderPCM16Bwb: {
         // 32 bytes per ms; 16 timestamps per ms.
         SplitBySamples(packet, 32, 16, &new_packets);
         break;
       }
-      case kDecoderPCM16Bswb32kHz: {
+      case NetEqDecoder::kDecoderPCM16Bswb32kHz: {
         // 64 bytes per ms; 32 timestamps per ms.
         SplitBySamples(packet, 64, 32, &new_packets);
         break;
       }
-      case kDecoderPCM16Bswb48kHz: {
+      case NetEqDecoder::kDecoderPCM16Bswb48kHz: {
         // 96 bytes per ms; 48 timestamps per ms.
         SplitBySamples(packet, 96, 48, &new_packets);
         break;
       }
-      case kDecoderPCM16B_2ch: {
+      case NetEqDecoder::kDecoderPCM16B_2ch: {
         // 2 * 16 bytes per ms; 8 timestamps per ms.
         SplitBySamples(packet, 2 * 16, 8, &new_packets);
         break;
       }
-      case kDecoderPCM16Bwb_2ch: {
+      case NetEqDecoder::kDecoderPCM16Bwb_2ch: {
         // 2 * 32 bytes per ms; 16 timestamps per ms.
         SplitBySamples(packet, 2 * 32, 16, &new_packets);
         break;
       }
-      case kDecoderPCM16Bswb32kHz_2ch: {
+      case NetEqDecoder::kDecoderPCM16Bswb32kHz_2ch: {
         // 2 * 64 bytes per ms; 32 timestamps per ms.
         SplitBySamples(packet, 2 * 64, 32, &new_packets);
         break;
       }
-      case kDecoderPCM16Bswb48kHz_2ch: {
+      case NetEqDecoder::kDecoderPCM16Bswb48kHz_2ch: {
         // 2 * 96 bytes per ms; 48 timestamps per ms.
         SplitBySamples(packet, 2 * 96, 48, &new_packets);
         break;
       }
-      case kDecoderPCM16B_5ch: {
+      case NetEqDecoder::kDecoderPCM16B_5ch: {
         // 5 * 16 bytes per ms; 8 timestamps per ms.
         SplitBySamples(packet, 5 * 16, 8, &new_packets);
         break;
       }
-      case kDecoderILBC: {
+      case NetEqDecoder::kDecoderILBC: {
         size_t bytes_per_frame;
         int timestamps_per_frame;
         if (packet->payload_length >= 950) {