[Chrome OS]Implement MediaStorageUtil::GetDeviceInfoForPath function to support media gallery permi…

chrome/browser/system_monitor/media_storage_util_chromeos.cc

+// 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.
+
+// Chrome OS specific implementation of chrome::MediaStorageUtil.
+
+#include "chrome/browser/system_monitor/media_storage_util.h"
+
+#include "base/file_path.h"
+#include "base/string16.h"
+#include "base/system_monitor/system_monitor.h"
+#include "chrome/browser/system_monitor/media_transfer_protocol_device_observer_chromeos.h"
+#include "chrome/browser/system_monitor/removable_device_notifications_chromeos.h"
+
+namespace chrome {
+
+using base::SystemMonitor;
+using chromeos::mtp::MediaTransferProtocolDeviceObserverCros;
+using chromeos::RemovableDeviceNotificationsCros;
+
+// static
+void MediaStorageUtil::GetDeviceInfoFromPathImpl(const FilePath& path,
+                                                 std::string* device_id,
+                                                 string16* device_name,
+                                                 FilePath* relative_path) {
+  // Check if the |path| belongs to a removable mass storage device.
+  RemovableDeviceNotificationsCros* mass_storage_tracker =
+      RemovableDeviceNotificationsCros::GetInstance();
+  DCHECK(mass_storage_tracker);
+  base::SystemMonitor::RemovableStorageInfo device_info;
+  bool found_device = mass_storage_tracker->GetDeviceInfoForPath(path,
+                                                                 &device_info);
+  if (!found_device) {
+    // Check if the |path| belongs to a mtp storage device.
+    MediaTransferProtocolDeviceObserverCros * mtp_device_tracker =
+        MediaTransferProtocolDeviceObserverCros::GetInstance();
+    if (!mtp_device_tracker->GetStorageInfoForPath(path, &device_info))
+      return;  // No matching device found.

[Lei Zhang, 2012/09/16 00:17:05]

This makes me think GetDeviceInfoFromPath() should return a bool. Otherwise how
do you know the returned info is valid?

[vandebo (ex-Chrome), 2012/09/16 00:31:44]

The function can fail, so we should propagate that out.

[kmadhusu, 2012/09/16 22:35:42]

Done.

[kmadhusu, 2012/09/16 22:35:42]

Modified the function signature to return bool.

+  }
+
+  if (device_id)
+    *device_id = device_info.device_id;
+  if (device_name)
+    *device_name = device_info.name;
+  if (relative_path) {
+    *relative_path = FilePath();
+    FilePath mount_point(device_info.location);
+    mount_point.AppendRelativePath(path, relative_path);
+  }
+}
+
+}  // namespace chrome