PPAPI: Add PluginPrivateFileSystem

ppapi/shared_impl/file_system_util.h

Index: ppapi/shared_impl/file_system_util.h
diff --git a/ppapi/shared_impl/file_system_util.h b/ppapi/shared_impl/file_system_util.h
index 2495a82bee7f10a30069734236d2374fa31d5124..5b39f6975780fcd33bfafd0086a024dc8df7090e 100644
--- a/ppapi/shared_impl/file_system_util.h
+++ b/ppapi/shared_impl/file_system_util.h
@@ -5,7 +5,10 @@
 #ifndef PPAPI_SHARED_IMPL_FILE_SYSTEM_UTIL_H_
 #define PPAPI_SHARED_IMPL_FILE_SYSTEM_UTIL_H_
 
+#include <string>
+
 #include "ppapi/c/pp_file_info.h"
+#include "ppapi/c/private/ppb_isolated_file_system_private.h"
 #include "ppapi/shared_impl/ppapi_shared_export.h"
 #include "webkit/common/fileapi/file_system_types.h"
 
@@ -19,6 +22,9 @@ PPAPI_SHARED_EXPORT bool FileSystemTypeIsValid(PP_FileSystemType type);
 
 PPAPI_SHARED_EXPORT bool FileSystemTypeHasQuota(PP_FileSystemType type);
 
+PPAPI_SHARED_EXPORT std::string IsolatedFileSystemTypeToRootName(
+    PP_IsolatedFileSystemType_Private type);
+
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_FILE_SYSTEM_UTIL_H_