Splitting media filter's Initialize() into Create() + callback and Seek() + callback.

media/filters/file_data_source.h

 // Copyright (c) 2009 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_FILTERS_FILE_DATA_SOURCE_H_
 #define MEDIA_FILTERS_FILE_DATA_SOURCE_H_
 
 #include <string>
 
 #include "base/lock.h"
 #include "media/base/filters.h"
 #include "testing/gtest/include/gtest/gtest_prod.h"
 
 namespace media {
 
 // Basic data source that treats the URL as a file path, and uses the file
 // system to read data for a media pipeline.
 class FileDataSource : public DataSource {
  public:
   // Public method to get a filter factory for the FileDataSource.
   static FilterFactory* CreateFactory() {
     return new FilterFactoryImpl0<FileDataSource>();
   }
 
   // Implementation of MediaFilter.
   virtual void Stop();
 
   // Implementation of DataSource.
-  virtual bool Initialize(const std::string& url);
+  virtual void Initialize(const std::string& url, FilterCallback* callback);
   virtual const MediaFormat& media_format();
   virtual size_t Read(uint8* data, size_t size);
   virtual bool GetPosition(int64* position_out);
   virtual bool SetPosition(int64 position);
   virtual bool GetSize(int64* size_out);
   virtual bool IsSeekable();
 
  private:
   // Only allow factories and tests to create this object.
   //
   // TODO(scherkus): I'm getting tired of these factories getting in the way
   // of my tests!!!
   FRIEND_TEST(FileDataSourceTest, OpenFile);
   FRIEND_TEST(FileDataSourceTest, ReadData);
+  FRIEND_TEST(FileDataSourceTest, Seek);
   friend class FilterFactoryImpl0<FileDataSource>;
   FileDataSource();
   virtual ~FileDataSource();
 
   // File handle.  NULL if not initialized or an error occurs.
   FILE* file_;
 
   // Size of the file in bytes.
   int64 file_size_;
 
   // Media format handed out by the DataSource::GetMediaFormat method.
   MediaFormat media_format_;
 
   // Critical section that protects all of the DataSource methods to prevent
   // a Stop from happening while in the middle of a file I/O operation.
   // TODO(ralphl): Ideally this would use asynchronous I/O or we will know
   // that we will block for a short period of time in reads.  Otherwise, we can
   // hang the pipeline Stop.
   Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(FileDataSource);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FILE_DATA_SOURCE_H_