[Media Gallery] Added code to support mtp device media file system on Windows.

chrome/browser/media_gallery/win/mtp_device_object_entry.h

+// Copyright (c) 2012 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_GALLERY_WIN_MTP_DEVICE_OBJECT_ENTRY_H_
+#define CHROME_BROWSER_MEDIA_GALLERY_WIN_MTP_DEVICE_OBJECT_ENTRY_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/string16.h"
+#include "base/time.h"
+
+namespace chrome {
+
+// MTPDeviceObjectEntry contains information about the media transfer protocol

[Lei Zhang, 2013/01/14 20:49:02]

This comment is not helpful. It just says foo contains info about foo. It might
be more helpful to know what Windows data structure this is capturing
information from.

[kmadhusu, 2013/01/15 19:08:17]

Rephrased the comment to include details about the interface that is used to
retrieve the object property values. MSDN documentation only provides details
about the interface that is used to retrieve the values and do not specify any
data structure name.

+// device (MTP) object entry.
+struct MTPDeviceObjectEntry {
+  MTPDeviceObjectEntry();  // Necessary for STL.
+  MTPDeviceObjectEntry(const string16& object_id,
+                       const string16& object_name,
+                       bool is_directory,
+                       int64 size,
+                       const base::Time& last_modified_time);
+
+  // The object identifier, e.g. "o299".

[Lei Zhang, 2013/01/14 20:49:02]

Where does this ID come from?

[kmadhusu, 2013/01/15 19:08:17]

ID is obtained from IEnumPortableDeviceObjectIDs interface.

+  string16 object_id;
+
+  // Friendly name of the object, e.g. "IMG_9911.jpeg".

[Lei Zhang, 2013/01/14 20:49:02]

Is this always just the file name or the full path?

[kmadhusu, 2013/01/15 19:08:17]

This field always store the file name.

+  string16 name;
+
+  // True if the current object is a directory/folder/album content type.
+  bool is_directory;
+
+  // The object file size in bytes, e.g. "882992".
+  int64 size;
+
+  // Last modified time of the object.
+  base::Time last_modified_time;
+};
+
+typedef std::vector<MTPDeviceObjectEntry> MTPDeviceObjectEntries;
+
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_MEDIA_GALLERY_WIN_MTP_DEVICE_OBJECT_ENTRY_H_