Make the shmem-specific functions in file_util.h POSIX-only.

base/file_util_win.cc

Index: base/file_util_win.cc
diff --git a/base/file_util_win.cc b/base/file_util_win.cc
index f8d7f7b8e7030c8f303d69acc1cff89e8c6f75c2..94b545a5f21888f286528c6633046ff64812992b 100644
--- a/base/file_util_win.cc
+++ b/base/file_util_win.cc
@@ -254,10 +254,6 @@ bool GetTempDir(FilePath* path) {
   return true;
 }
 
-bool GetShmemTempDir(bool executable, FilePath* path) {
-  return GetTempDir(path);
-}
-
 FilePath GetHomeDir() {
   char16 result[MAX_PATH];
   if (SUCCEEDED(SHGetFolderPath(NULL, CSIDL_PROFILE, NULL, SHGFP_TYPE_CURRENT,
@@ -291,11 +287,6 @@ bool CreateTemporaryFile(FilePath* path) {
   return false;
 }
 
-FILE* CreateAndOpenTemporaryShmemFile(FilePath* path, bool executable) {
-  ThreadRestrictions::AssertIOAllowed();
-  return CreateAndOpenTemporaryFile(path);
-}
-
 // On POSIX we have semantics to create and open a temporary file
 // atomically.
 // TODO(jrg): is there equivalent call to use on Windows instead of