Media: Add thumbnail extraction to AudioVideoMetadataExtractor.

media/base/audio_video_metadata_extractor.h

 // Copyright 2014 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_VIDEO_METADATA_EXTRACTOR_H_
 #define MEDIA_BASE_AUDIO_VIDEO_METADATA_EXTRACTOR_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 20 matching lines @@
     TagDictionary tags;
   };
 
   typedef std::vector<StreamInfo> StreamInfoVector;
 
   AudioVideoMetadataExtractor();
   ~AudioVideoMetadataExtractor();
 
   // Returns whether or not the fields were successfully extracted. Should only
   // be called once.
-  bool Extract(DataSource* source);
+  bool Extract(DataSource* source, bool extract_attached_pics);
 
   // Returns -1 if we cannot extract the duration. In seconds.
   double duration() const;
 
   // Returns -1 for containers without video.
   int width() const;
   int height() const;
 
   // Returns -1 if undefined.
   int rotation() const;
 
   // Returns -1 or an empty string if the value is undefined.
   const std::string& album() const;
   const std::string& artist() const;
   const std::string& comment() const;
   const std::string& copyright() const;
   const std::string& date() const;
   int disc() const;
   const std::string& encoder() const;
   const std::string& encoded_by() const;
   const std::string& genre() const;
   const std::string& language() const;
   const std::string& title() const;
   int track() const;
 
   // First element is the container. Subsequent elements are the child streams.
   const StreamInfoVector& stream_infos() const;
 
+  // Empty if Extract call did not request attached images, or if no attached
+  // images were found.
+  const std::vector<std::string>& attached_images_bytes() const;
+
  private:
   void ExtractDictionary(AVDictionary* metadata, TagDictionary* raw_tags);
 
   bool extracted_;
 
   int duration_;
   int width_;
   int height_;
 
   std::string album_;
   std::string artist_;
   std::string comment_;
   std::string copyright_;
   std::string date_;
   int disc_;
   std::string encoder_;
   std::string encoded_by_;
   std::string genre_;
   std::string language_;
   int rotation_;
   std::string title_;
   int track_;
 
   StreamInfoVector stream_infos_;
 
+  std::vector<std::string> attached_images_bytes_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioVideoMetadataExtractor);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_VIDEO_METADATA_EXTRACTOR_H_