Rename 'harddisk' to 'fixed' for storage unit type

chrome/common/extensions/api/experimental_system_info_storage.idl

 // 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.
 
 namespace experimental.systemInfo.storage {
 
   enum StorageUnitType {
-    // Unknow storage type.
-    unknown,
-    // Hard disk.
-    harddisk,
-    // Removable storage, e.g.USB device.
-    removable
+    // The storage has fixed media, e.g. hard disk or SSD.
+    fixed,
+    // The storage is removable, e.g. USB flash drive.
+    removable,
+    // The storage type is unknown.
+    unknown
   };
 
   dictionary StorageUnitInfo {
     // The unique id of the storage unit.
     DOMString id;
-    // The type of storage device. The value is one of the constants defined
-    // for this type.
+    // The media type of the storage unit.
     StorageUnitType type;
     // The total amount of the storage space, in bytes.
     double capacity;
     // The available amount of the storage space, in bytes.
     double availableCapacity;
   };
 
   dictionary StorageChangeInfo {
     // The uniue id of the storage unit already changed.
     DOMString id;
@@ skipping 16 matching lines @@
 
     // Fired when a new removable storage is attached to the system.
     static void onAttached(StorageUnitInfo info);
 
     // Fired when a removable storage is detached from the system.
     static void onDetached(DOMString id);
   };
  
 };