Don't allow path traversal paths on the base file helpers

base/platform_file_win.cc

Index: base/platform_file_win.cc
===================================================================
--- base/platform_file_win.cc	(revision 175095)
+++ base/platform_file_win.cc	(working copy)
@@ -9,11 +9,10 @@
 #include "base/threading/thread_restrictions.h"
 
 namespace base {
-
-PlatformFile CreatePlatformFile(const FilePath& name,
-                                int flags,
-                                bool* created,
-                                PlatformFileError* error_code) {
+PlatformFile CreatePlatformFileAllowTraversal(const FilePath& name,
+                                              int flags,
+                                              bool* created,
+                                              PlatformFileError* error_code) {
   base::ThreadRestrictions::AssertIOAllowed();
 
   DWORD disposition = 0;