Media Galleries API Metadata: SafeMediaMetadataParser and IPCTunnelDataReader.

chrome/utility/media_galleries/media_metadata_parser.h

Index: chrome/utility/media_galleries/media_metadata_parser.h
diff --git a/chrome/utility/media_galleries/media_metadata_parser.h b/chrome/utility/media_galleries/media_metadata_parser.h
index 2f93de008d97202e5b3fba8d7360f074b575736d..c9c5b5e775d26be8868a878daec33529b8bfa594 100644
--- a/chrome/utility/media_galleries/media_metadata_parser.h
+++ b/chrome/utility/media_galleries/media_metadata_parser.h
@@ -25,9 +25,8 @@ class MediaMetadataParser {
   typedef extensions::api::media_galleries::MediaMetadata MediaMetadata;
   typedef base::Callback<void(scoped_ptr<MediaMetadata>)> MetadataCallback;
 
-  // Does not take ownership of |source|. The MIME type is sniffed in the
-  // browser process, as it's faster (and safe enough). When the user wants
-  // more metadata than just the MIME type, this class provides it.
+  // Does not take ownership of |source|. Caller is responsible for ensuring
+  // that |source| outlives this object.
   MediaMetadataParser(media::DataSource* source, const std::string& mime_type);
 
   ~MediaMetadataParser();