Include DirectoryExists to libbase_nacl_nonsfi.a.

DirectoryExists will be used by sandbox/ code for
nacl_helper_nonsfi. This CL is the preparation for it.

TEST=Run bots.
BUG=464663

Review URL: https://codereview.chromium.org/1056433002

Cr-Commit-Position: refs/heads/master@{#323286}


CrOS-Libchrome-Original-Commit: 1b30fcb34c1164b4c2bbb05fd64a7b7056ba69fb
diff --git a/base/files/file_util_posix.cc b/base/files/file_util_posix.cc
index dad8edd..b4a64ba 100644
--- a/base/files/file_util_posix.cc
+++ b/base/files/file_util_posix.cc
@@ -57,7 +57,6 @@
 
 namespace base {
 
-#if !defined(OS_NACL_NONSFI)
 namespace {
 
 #if defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL)
@@ -80,6 +79,7 @@
 }
 #endif  // !(defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL))
 
+#if !defined(OS_NACL_NONSFI)
 // Helper for NormalizeFilePath(), defined below.
 bool RealPath(const FilePath& path, FilePath* real_path) {
   ThreadRestrictions::AssertIOAllowed();  // For realpath().
@@ -182,9 +182,11 @@
   return result;
 }
 #endif  // defined(OS_LINUX)
+#endif  // !defined(OS_NACL_NONSFI)
 
 }  // namespace
 
+#if !defined(OS_NACL_NONSFI)
 FilePath MakeAbsoluteFilePath(const FilePath& input) {
   ThreadRestrictions::AssertIOAllowed();
   char full_path[PATH_MAX];
@@ -363,6 +365,7 @@
   ThreadRestrictions::AssertIOAllowed();
   return access(path.value().c_str(), W_OK) == 0;
 }
+#endif  // !defined(OS_NACL_NONSFI)
 
 bool DirectoryExists(const FilePath& path) {
   ThreadRestrictions::AssertIOAllowed();
@@ -371,7 +374,6 @@
     return S_ISDIR(file_info.st_mode);
   return false;
 }
-#endif  // !defined(OS_NACL_NONSFI)
 
 bool ReadFromFD(int fd, char* buffer, size_t bytes) {
   size_t total_read = 0;