Convert base::MemoryMappedFile to use File instead of PlatformFile.

media/filters/file_data_source.h

Index: media/filters/file_data_source.h
diff --git a/media/filters/file_data_source.h b/media/filters/file_data_source.h
index c0164dac5745ad4346083ecc2bc2c4224bb5ef60..817e2b9be6d412c6438b4c31a4b47dda57bba89d 100644
--- a/media/filters/file_data_source.h
+++ b/media/filters/file_data_source.h
@@ -7,9 +7,9 @@
 
 #include <string>
 
+#include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/files/memory_mapped_file.h"
-#include "base/platform_file.h"
 #include "media/base/data_source.h"
 
 namespace media {
@@ -19,10 +19,10 @@ namespace media {
 class MEDIA_EXPORT FileDataSource : public DataSource {
  public:
   FileDataSource();
+  explicit FileDataSource(base::File file);
   virtual ~FileDataSource();
 
   bool Initialize(const base::FilePath& file_path);
-  bool InitializeFromPlatformFile(const base::PlatformFile& file);
 
   // Implementation of DataSource.
   virtual void set_host(DataSourceHost* host) OVERRIDE;