Do not call stat() when reading directories via File API.

chrome/browser/media_galleries/linux/mtp_device_task_helper.h

 // Copyright 2013 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_MEDIA_GALLERIES_LINUX_MTP_DEVICE_TASK_HELPER_H_
 #define CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_TASK_HELPER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/media_galleries/fileapi/mtp_device_async_delegate.h"
 #include "device/media_transfer_protocol/mtp_file_entry.pb.h"
 #include "storage/browser/fileapi/async_file_util.h"
 
 class MTPReadFileWorker;
 struct SnapshotRequestInfo;
 
 // MTPDeviceTaskHelper dispatches the media transfer protocol (MTP) device
 // operation requests (such as GetFileInfo, ReadDirectory, CreateSnapshotFile,
 // OpenStorage and CloseStorage) to the MediaTransferProtocolManager.
 // MTPDeviceTaskHelper lives on the UI thread. MTPDeviceTaskHelperMapService
 // owns the MTPDeviceTaskHelper objects. MTPDeviceTaskHelper is instantiated per
 // MTP device storage.
 class MTPDeviceTaskHelper {
  public:
+  struct MTPEntry {
+    MTPEntry();
+
+    uint32_t file_id;
+    std::string name;
+    base::File::Info file_info;
+  };
+
+  typedef std::vector<MTPEntry> MTPEntries;
+
   typedef base::Callback<void(bool succeeded)> OpenStorageCallback;
 
   typedef MTPDeviceAsyncDelegate::GetFileInfoSuccessCallback
       GetFileInfoSuccessCallback;
 
   typedef base::Closure CreateDirectorySuccessCallback;
 
-  // NOTE: The file names in the entry list have their file id appended at the
-  // end. e.g. foo.jpg with file id 45 becomes foo.jpg,45.
-  typedef base::Callback<void(const storage::AsyncFileUtil::EntryList& entries,
-                              bool has_more)> ReadDirectorySuccessCallback;
+  typedef base::Callback<void(const MTPEntries& entries, bool has_more)>
+      ReadDirectorySuccessCallback;
 
   typedef base::Closure RenameObjectSuccessCallback;
 
   typedef base::Closure CopyFileFromLocalSuccessCallback;
 
   typedef base::Closure DeleteObjectSuccessCallback;
 
   typedef MTPDeviceAsyncDelegate::ErrorCallback ErrorCallback;
 
   MTPDeviceTaskHelper();
@@ skipping 179 matching lines @@
   // Used to handle WriteDataInfoSnapshotFile request.
   scoped_ptr<MTPReadFileWorker> read_file_worker_;
 
   // For callbacks that may run after destruction.
   base::WeakPtrFactory<MTPDeviceTaskHelper> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MTPDeviceTaskHelper);
 };
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_LINUX_MTP_DEVICE_TASK_HELPER_H_