Add link to RFC2361 for WAV codecs as I always have a hard time finding said spec.

net/base/mime_util.cc

 // Copyright (c) 2011 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 <map>
 #include <string>
 
 #include "net/base/mime_util.h"
 #include "net/base/platform_mime_util.h"
 
@@ skipping 240 matching lines @@
   "audio/mp3",
   "audio/x-mp3",
   "audio/mpeg",
 #endif
 };
 
 // List of supported codecs when passed in with <source type="...">.
 //
 // Refer to http://wiki.whatwg.org/wiki/Video_type_parameters#Browser_Support
 // for more information.
+//
+// The codecs for WAV are integers as defined in Appendix A of RFC2361:
+// http://tools.ietf.org/html/rfc2361
 static const char* const supported_media_codecs[] = {
 #if defined(GOOGLE_CHROME_BUILD) || defined(USE_PROPRIETARY_CODECS)
   "avc1",
   "mp4a",
 #endif
 #if defined(ENABLE_MEDIA_CODEC_THEORA)
   "theora",
 #endif
   "vorbis",
   "vp8",
-  "1"  // PCM for WAV.
+  "1"  // WAVE_FORMAT_PCM.
 };
 
 // Note: does not include javascript types list (see supported_javascript_types)
 static const char* const supported_non_image_types[] = {
   "text/cache-manifest",
   "text/html",
   "text/xml",
   "text/xsl",
   "text/plain",
   // Many users complained about css files served for
@@ skipping 456 matching lines @@
 
   GetExtensionsFromHardCodedMappings(secondary_mappings,
                                      arraysize(secondary_mappings),
                                      mime_type,
                                      &unique_extensions);
 
   HashSetToVector(&unique_extensions, extensions);
 }
 
 }  // namespace net