Move DataSource::SetPreload() to BufferedDataSource.

media/media.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
     # Override to dynamically link the PulseAudio library.
     'use_pulseaudio%': 0,
   },
@@ skipping 132 matching lines @@
         'base/media_log_event.h',
         'base/media_posix.cc',
         'base/media_switches.cc',
         'base/media_switches.h',
         'base/media_win.cc',
         'base/message_loop_factory.cc',
         'base/message_loop_factory.h',
         'base/pipeline.cc',
         'base/pipeline.h',
         'base/pipeline_status.h',
-        'base/preload.h',
         'base/seekable_buffer.cc',
         'base/seekable_buffer.h',
         'base/state_matrix.cc',
         'base/state_matrix.h',
         'base/stream_parser.cc',
         'base/stream_parser.h',
         'base/video_decoder_config.cc',
         'base/video_decoder_config.h',
         'base/video_frame.cc',
         'base/video_frame.h',
@@ skipping 785 matching lines @@
             '../third_party/ffmpeg/ffmpeg.gyp:ffmpeg',
           ],
           'sources': [
             'tools/media_bench/media_bench.cc',
           ],
         },
       ],
     }]
   ],
 }