[fsp] Add support for providing thumbnails.

chrome/browser/chromeos/file_system_provider/fileapi/file_stream_reader.h

 // Copyright 2014 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 CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_READER_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_READER_H_
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "webkit/browser/blob/file_stream_reader.h"
 #include "webkit/browser/fileapi/file_system_url.h"
 
 namespace chromeos {
 namespace file_system_provider {
 
 struct EntryMetadata;
 class ProvidedFileSystemInterface;
 
@@ skipping 41 matching lines @@
 
   // Called when opening a file is completed with either a success or an error.
   void OnOpenFileCompleted(
       const base::Closure& pending_closure,
       const net::Int64CompletionCallback& error_callback,
       base::File::Error result);
 
   // Called when initialization is completed with either a success or an error.
   void OnInitializeCompleted(const base::Closure& pending_closure,
                              const net::Int64CompletionCallback& error_callback,
-                             const EntryMetadata& metadata,
+                             scoped_ptr<EntryMetadata> metadata,
                              base::File::Error result);
 
   // Called when a file system provider returns chunk of read data. Note, that
   // this may be called multiple times per single Read() call, as long as
   // |has_more| is set to true. |result| is set to success only if reading is
   // successful, and the file has not changed while reading.
   void OnReadChunkReceived(const net::CompletionCallback& callback,
                            int chunk_length,
                            bool has_more,
                            base::File::Error result);
 
   // Called when fetching length of the file is completed with either a success
   // or an error.
   void OnGetMetadataForGetLengthReceived(
       const net::Int64CompletionCallback& callback,
-      const EntryMetadata& metadata,
+      scoped_ptr<EntryMetadata> metadata,
       base::File::Error result);
 
   // Same as Read(), but called after initializing is completed.
   void ReadAfterInitialized(scoped_refptr<net::IOBuffer> buffer,
                             int buffer_length,
                             const net::CompletionCallback& callback);
 
   // Same as GetLength(), but called after initializing is completed.
   void GetLengthAfterInitialized(const net::Int64CompletionCallback& callback);
 
   storage::FileSystemURL url_;
   int64 current_offset_;
   int64 current_length_;
   base::Time expected_modification_time_;
   scoped_refptr<OperationRunner> runner_;
   State state_;
 
   base::WeakPtrFactory<FileStreamReader> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(FileStreamReader);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_READER_H_