Opus extension to mimetype map so files with .opus play instead of download,...

Opus extension to mimetype map so files with .opus play instead of download, if enabled with --enable-opus-playback.
BUG=174280
TESTED=try bots
Review URL: https://codereview.chromium.org/12221108

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@182061 0039d316-1c4b-4281-b951-d872f2087c98

net/base/mime_util.cc

@@ -129,7 +129,7 @@ static const MimeInfo primary_mappings[] = {
   { "audio/x-m4a", "m4a" },
   { "audio/mp3", "mp3" },
   { "video/ogg", "ogv,ogm" },
-  { "audio/ogg", "ogg,oga" },
+  { "audio/ogg", "ogg,oga,opus" },
   { "video/webm", "webm" },
   { "audio/webm", "webm" },
   { "audio/wav", "wav" },