Clean up histogram'd media enum max values.

media/filters/stream_parser_factory.cc

 // Copyright (c) 2013 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.
 
 #include "media/filters/stream_parser_factory.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ skipping 31 matching lines @@
     HISTOGRAM_UNKNOWN,
     HISTOGRAM_VP8,
     HISTOGRAM_VP9,
     HISTOGRAM_VORBIS,
     HISTOGRAM_H264,
     HISTOGRAM_MPEG2AAC,
     HISTOGRAM_MPEG4AAC,
     HISTOGRAM_EAC3,
     HISTOGRAM_MP3,
     HISTOGRAM_OPUS,
-    HISTOGRAM_MAX  // Must be the last entry.
+    HISTOGRAM_MAX = HISTOGRAM_OPUS  // Must be equal to last entry!

[rileya (GONE FROM CHROMIUM), 2014/01/29 19:24:11]

HISTOGRAM_MAX now seems like kind of a misnomer, as it isn't the max we're using
for the UMA call, but rather the max of the enum itself. Given that everything
else is prefixed with HISTOGRAM_ I suppose this is alright though...

[Ami GONE FROM CHROMIUM, 2014/01/29 21:29:02]

Can this enum type be replaced with a union of audio & video codec enum?

   };
 
   const char* pattern;
   Type type;
   CodecIDValidatorFunction validator;
   HistogramTag tag;
 };
 
 typedef StreamParser* (*ParserFactoryFunction)(
     const std::vector<std::string>& codecs,
@@ skipping 327 matching lines @@
                          log_cb,
                          &factory_function,
                          &audio_codecs,
                          &video_codecs)) {
     *has_audio = !audio_codecs.empty();
     *has_video = !video_codecs.empty();
 
     // Log the number of codecs specified, as well as the details on each one.
     UMA_HISTOGRAM_COUNTS_100("Media.MSE.NumberOfTracks", codecs.size());
     for (size_t i = 0; i < audio_codecs.size(); ++i) {
-      UMA_HISTOGRAM_ENUMERATION(
-          "Media.MSE.AudioCodec", audio_codecs[i], CodecInfo::HISTOGRAM_MAX);
+      UMA_HISTOGRAM_ENUMERATION("Media.MSE.AudioCodec",
+                                audio_codecs[i],
+                                CodecInfo::HISTOGRAM_MAX + 1);
     }
     for (size_t i = 0; i < video_codecs.size(); ++i) {
-      UMA_HISTOGRAM_ENUMERATION(
-          "Media.MSE.VideoCodec", video_codecs[i], CodecInfo::HISTOGRAM_MAX);
+      UMA_HISTOGRAM_ENUMERATION("Media.MSE.VideoCodec",
+                                video_codecs[i],
+                                CodecInfo::HISTOGRAM_MAX + 1);
     }
 
     stream_parser.reset(factory_function(codecs, log_cb));
   }
 
   return stream_parser.Pass();
 }
 
 }  // namespace media