[CrosDisksClient] Determine device type from DeviceMediaType property sent by cros-disks.

chrome/browser/chromeos/disks/disk_mount_manager.h

 // Copyright (c) 2011 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_DISKS_DISK_MOUNT_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_DISKS_DISK_MOUNT_MANAGER_H_
 #pragma once
 
 #include <map>
 
@@ skipping 215 matching lines @@
 
   // Returns corresponding string to |type| like "device" or "file".
   static std::string MountTypeToString(MountType type);
 
   // The inverse function of MountTypeToString.
   static MountType MountTypeFromString(const std::string& type_str);
 
   // Returns corresponding string to |type| like "unknown_filesystem".
   static std::string MountConditionToString(MountCondition type);
 
+  // Returns corresponding string to |type|, like "sd", "usb".
+  static std::string DeviceTypeToString(DeviceType type);
+
   // Creates the global DiskMountManager instance.
   static void Initialize();
 
   // Similar to Initialize(), but can inject an alternative
   // DiskMountManager such as MockDiskMountManager for testing.
   // The injected object will be owned by the internal pointer and deleted
   // by Shutdown().
   static void InitializeForTesting(DiskMountManager* disk_mount_manager);
 
   // Destroys the global DiskMountManager instance if it exists.
   static void Shutdown();
 
   // Returns a pointer to the global DiskMountManager instance.
   // Initialize() should already have been called.
   static DiskMountManager* GetInstance();
 };
 
 }  // namespace disks
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_DISKS_DISK_MOUNT_MANAGER_H_