Implement the filesystem proxy. This allows the FileRef tests to pass in the...

ppapi/c/dev/pp_file_info_dev.h

 /* Copyright (c) 2010 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 PPAPI_C_DEV_PP_FILE_INFO_DEV_H_
 #define PPAPI_C_DEV_PP_FILE_INFO_DEV_H_
 
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_stdint.h"
 #include "ppapi/c/pp_time.h"
 
 typedef enum {
   PP_FILETYPE_REGULAR,
   PP_FILETYPE_DIRECTORY,
   PP_FILETYPE_OTHER  /* A catch-all for unidentified types. */
 } PP_FileType_Dev;
 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_FileType_Dev, 4);
 
 typedef enum {
+  PP_FILESYSTEMTYPE_NONE = 0,  /* For identifying invalid return values. */
   PP_FILESYSTEMTYPE_EXTERNAL,
   PP_FILESYSTEMTYPE_LOCALPERSISTENT,
   PP_FILESYSTEMTYPE_LOCALTEMPORARY
 } PP_FileSystemType_Dev;
 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_FileSystemType_Dev, 4);
 
 struct PP_FileInfo_Dev {
   int64_t size;  /* Measured in bytes */
   PP_FileType_Dev type;
   PP_FileSystemType_Dev system_type;
   PP_Time creation_time;
   PP_Time last_access_time;
   PP_Time last_modified_time;
 };
 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_FileInfo_Dev, 40);
 
 #endif  /* PPAPI_C_DEV_PP_FILE_INFO_DEV_H_ */