ChromeOS: Implement MediaTransferProtocolManager observer.

chrome/browser/system_monitor/chromeos/media_transfer_protocol_device_observer.h

Index: chrome/browser/system_monitor/chromeos/media_transfer_protocol_device_observer.h
diff --git a/chrome/browser/system_monitor/chromeos/media_transfer_protocol_device_observer.h b/chrome/browser/system_monitor/chromeos/media_transfer_protocol_device_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..f31c3e23598271df99efee0a39434b1cddab65c4
--- /dev/null
+++ b/chrome/browser/system_monitor/chromeos/media_transfer_protocol_device_observer.h
@@ -0,0 +1,62 @@
+// 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_SYSTEM_MONITOR_CHROMEOS_MEDIA_TRANSFER_PROTOCOL_DEVICE_OBSERVER_H_
+#define CHROME_BROWSER_SYSTEM_MONITOR_CHROMEOS_MEDIA_TRANSFER_PROTOCOL_DEVICE_OBSERVER_H_
+
+#include <map>
+#include <string>
+
+#include "base/string16.h"
+#include "chrome/browser/chromeos/mtp/media_transfer_protocol_manager.h"
+
+namespace chromeos {
+namespace mtp {
+
+// Gets the mtp device information given a |storage_name|. On success,
+// fills in |id|, |name| and |location|.
+typedef void (*GetStorageInfoFunc)(const std::string& storage_name,
+                                   std::string* id,
+                                   string16* name,
+                                   std::string* location);
+
+// Helper class to send MTP storage attachment and detachment events to
+// SystemMonitor.
+class MediaTransferProtocolDeviceObserver
+      : public MediaTransferProtocolManager::Observer {
+ public:
+  MediaTransferProtocolDeviceObserver();
+
+  // Only used in unit tests.

[Lei Zhang, 2012/09/10 18:18:01]

You can probably mark this and StorageChanged() as protected, and just write a
simple TestMediaTransferProtocolDeviceObserver in the unit test.

[kmadhusu, 2012/09/11 01:50:19]

Done.

+  explicit MediaTransferProtocolDeviceObserver(
+      GetStorageInfoFunc get_storage_info_func);
+
+  virtual ~MediaTransferProtocolDeviceObserver();
+
+  // MediaTransferProtocolManager::Observer implementation.
+  // Exposed for unit tests.
+  virtual void StorageChanged(bool is_attached,
+                              const std::string& storage_name) OVERRIDE;
+
+ private:
+  // Mapping of storage name and device id.
+  typedef std::map<std::string, std::string> StorageNameAndIdMap;
+
+  // Enumerate existing mtp storage devices.
+  void EnumerateStorages();
+
+  // Map of all attached mtp devices.
+  StorageNameAndIdMap storage_map_;
+
+  // Function handler to get storage information. This is useful to set a mock
+  // handler for unit testing.
+  GetStorageInfoFunc get_storage_info_func_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaTransferProtocolDeviceObserver);
+};
+
+}  // namespace mtp
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_SYSTEM_MONITOR_CHROMEOS_MEDIA_TRANSFER_PROTOCOL_DEVICE_OBSERVER_H_