Clean up histogram'd media enum max values.

media/base/audio_decoder_config.h

 // Copyright (c) 2012 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.
 
 #ifndef MEDIA_BASE_AUDIO_DECODER_CONFIG_H_
 #define MEDIA_BASE_AUDIO_DECODER_CONFIG_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/time/time.h"
 #include "media/base/channel_layout.h"
 #include "media/base/media_export.h"
 #include "media/base/sample_format.h"
 
 namespace media {
 
 enum AudioCodec {
   // These values are histogrammed over time; do not change their ordinal
   // values.  When deleting a codec replace it with a dummy value; when adding a
-  // codec, do so at the bottom before kAudioCodecMax.
+  // codec, do so at the bottom before kAudioCodecMax, and update the value of
+  // kAudioCodecMax to equal the new codec.
   kUnknownAudioCodec = 0,
   kCodecAAC = 1,
   kCodecMP3 = 2,
   kCodecPCM = 3,
   kCodecVorbis = 4,
   kCodecFLAC = 5,
   kCodecAMR_NB = 6,
   kCodecAMR_WB = 7,
   kCodecPCM_MULAW = 8,
   kCodecGSM_MS = 9,
   kCodecPCM_S16BE = 10,
   kCodecPCM_S24BE = 11,
   kCodecOpus = 12,
   // kCodecEAC3 = 13,
   kCodecPCM_ALAW = 14,
   // DO NOT ADD RANDOM AUDIO CODECS!
   //
   // The only acceptable time to add a new codec is if there is production code
   // that uses said codec in the same CL.
 
-  // Must always be last!
-  kAudioCodecMax
+  // Must always be equal to the largest entry ever logged.
+  kAudioCodecMax = kCodecPCM_ALAW,
 };
 
 // TODO(dalecurtis): FFmpeg API uses |bytes_per_channel| instead of
 // |bits_per_channel|, we should switch over since bits are generally confusing
 // to work with.
 class MEDIA_EXPORT AudioDecoderConfig {
  public:
   // Constructs an uninitialized object. Clients should call Initialize() with
   // appropriate values before using.
   AudioDecoderConfig();
@@ skipping 65 matching lines @@
   base::TimeDelta codec_delay_;
 
   // Not using DISALLOW_COPY_AND_ASSIGN here intentionally to allow the compiler
   // generated copy constructor and assignment operator. Since the extra data is
   // typically small, the performance impact is minimal.
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_DECODER_CONFIG_H_