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

webrtc/modules/audio_coding/neteq/decoder_database.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 19 matching lines @@
     kInvalidSampleRate = -3,
     kDecoderExists = -4,
     kDecoderNotFound = -5,
     kInvalidPointer = -6
   };
 
   // Struct used to store decoder info in the database.
   struct DecoderInfo {
     // Constructors.
     DecoderInfo()
-        : codec_type(kDecoderArbitrary),
+        : codec_type(NetEqDecoder::kDecoderArbitrary),
           fs_hz(8000),
           decoder(NULL),
-          external(false) {
-    }
+          external(false) {}
     DecoderInfo(NetEqDecoder ct, int fs, AudioDecoder* dec, bool ext)
         : codec_type(ct),
           fs_hz(fs),
           decoder(dec),
           external(ext) {
     }
     // Destructor. (Defined in decoder_database.cc.)
     ~DecoderInfo();
 
     NetEqDecoder codec_type;
@@ skipping 90 matching lines @@
 
   DecoderMap decoders_;
   int active_decoder_;
   int active_cng_decoder_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(DecoderDatabase);
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_DECODER_DATABASE_H_