[fsp] Add support for providing thumbnails.

chrome/browser/chromeos/file_system_provider/fake_provided_file_system.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_FAKE_PROVIDED_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FAKE_PROVIDED_FILE_SYSTEM_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 56 matching lines @@
   // Fetches a pointer to a fake entry registered in the fake file system. If
   // found, then the result is written to |fake_entry| and true is returned.
   // Otherwise, false is returned. |fake_entry| must not be NULL.
   bool GetEntry(const base::FilePath& entry_path, FakeEntry* fake_entry) const;
 
   // ProvidedFileSystemInterface overrides.
   virtual AbortCallback RequestUnmount(
       const storage::AsyncFileUtil::StatusCallback& callback) OVERRIDE;
   virtual AbortCallback GetMetadata(
       const base::FilePath& entry_path,
+      ProvidedFileSystemInterface::MetadataFieldMask fields,
       const ProvidedFileSystemInterface::GetMetadataCallback& callback)
       OVERRIDE;
   virtual AbortCallback ReadDirectory(
       const base::FilePath& directory_path,
       const storage::AsyncFileUtil::ReadDirectoryCallback& callback) OVERRIDE;
   virtual AbortCallback OpenFile(const base::FilePath& file_path,
                                  OpenFileMode mode,
                                  const OpenFileCallback& callback) OVERRIDE;
   virtual AbortCallback CloseFile(
       int file_handle,
@@ skipping 70 matching lines @@
   base::CancelableTaskTracker tracker_;
 
   base::WeakPtrFactory<FakeProvidedFileSystem> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(FakeProvidedFileSystem);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FAKE_PROVIDED_FILE_SYSTEM_H_