GTTF: Add missing virtual destructors.

media/filters/ffmpeg_glue.h

 // Copyright (c) 2012 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.
 
 // FFmpegGlue is an interface between FFmpeg and Chrome used to proxy FFmpeg's
 // read and seek requests to Chrome's internal data structures.  The glue works
 // through the AVIO interface provided by FFmpeg.
 //
 // AVIO works through a special AVIOContext created through avio_alloc_context()
 // which is attached to the AVFormatContext used for demuxing.  The AVIO context
@@ skipping 20 matching lines @@
 
 struct AVFormatContext;
 struct AVIOContext;
 
 namespace media {
 
 class ScopedPtrAVFree;
 
 class MEDIA_EXPORT FFmpegURLProtocol {
  public:
+  virtual ~FFmpegURLProtocol() { }
+
   // Read the given amount of bytes into data, returns the number of bytes read
   // if successful, kReadError otherwise.
   virtual int Read(int size, uint8* data) = 0;
 
   // Returns true and the current file position for this file, false if the
   // file position could not be retrieved.
   virtual bool GetPosition(int64* position_out) = 0;
 
   // Returns true if the file position could be set, false otherwise.
   virtual bool SetPosition(int64 position) = 0;
@@ skipping 23 matching lines @@
   bool open_called_;
   AVFormatContext* format_context_;
   scoped_ptr_malloc<AVIOContext, ScopedPtrAVFree> avio_context_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegGlue);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FFMPEG_GLUE_H_