[PPAPI] Fix a bunch of spelling mistakes

ppapi/api/pp_file_info.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.
  */
 
 /**
  * This file defines three enumerations for use in the PPAPI C file IO APIs.
  */
 
 /**
@@ skipping 11 matching lines @@
 
 /**
  * The <code>PP_FileSystemType</code> enum contains file system type constants.
  */
 [assert_size(4)]
 enum PP_FileSystemType {
   /** For identified invalid return values */
   PP_FILESYSTEMTYPE_INVALID = 0,
   /** For external file system types */
   PP_FILESYSTEMTYPE_EXTERNAL = 1,
-  /** For local persistant file system types */
+  /** For local persistent file system types */
   PP_FILESYSTEMTYPE_LOCALPERSISTENT = 2,
   /** For local temporary file system types */
   PP_FILESYSTEMTYPE_LOCALTEMPORARY = 3
 };
 
 /**
  * The <code>PP_FileInfo</code> struct represents all information about a file,
  * such as size, type, and creation time.
  */
 [assert_size(40)]
@@ skipping 22 matching lines @@
    * This value represents the last time the file was accessed.
    */
   PP_Time last_access_time;
 
   /**
    * This value represents the last time the file was modified.
    */
   PP_Time last_modified_time;
 };