Implement media path filter

webkit/fileapi/file_system_operation_interface.h

Index: webkit/fileapi/file_system_operation_interface.h
diff --git a/webkit/fileapi/file_system_operation_interface.h b/webkit/fileapi/file_system_operation_interface.h
index 404c9f74e9e0a075e4fb8c06a64790b506916141..7ea0ae1f324e4bdc702be456f9fa17d025e2b8e8 100644
--- a/webkit/fileapi/file_system_operation_interface.h
+++ b/webkit/fileapi/file_system_operation_interface.h
@@ -74,12 +74,15 @@ class FileSystemOperationInterface {
            base::PlatformFile file,
            base::ProcessHandle peer_handle)> OpenFileCallback;
 
+  // Used for ReadDirectoryCallback.
+  typedef std::vector<base::FileUtilProxy::Entry> FileEntryList;
+
   // Used for ReadDirectory(). |result| is the return code of the operation,
   // |file_list| is the list of files read, and |has_more| is true if some files
   // are yet to be read.
   typedef base::Callback<
       void(base::PlatformFileError result,
-           const std::vector<base::FileUtilProxy::Entry>& file_list,
+           const FileEntryList& file_list,
            bool has_more)> ReadDirectoryCallback;
 
   // Used for CreateSnapshotFile(). (Please see the comment at