Update from https://crrev.com/306655

sandbox/linux/services/credentials.h

Index: sandbox/linux/services/credentials.h
diff --git a/sandbox/linux/services/credentials.h b/sandbox/linux/services/credentials.h
index 99f8f322dff62c9814ee131d97ec31fab4b1bbaf..c6a6eb007151c634a93aba7e9b0706fdf00328de 100644
--- a/sandbox/linux/services/credentials.h
+++ b/sandbox/linux/services/credentials.h
@@ -27,25 +27,6 @@ class SANDBOX_EXPORT Credentials {
   Credentials();
   ~Credentials();
 
-  // Returns the number of file descriptors in the current process's FD
-  // table, excluding |proc_fd|, which should be a file descriptor for
-  // /proc.
-  int CountOpenFds(int proc_fd);
-
-  // Checks whether the current process has any directory file descriptor open.
-  // Directory file descriptors are "capabilities" that would let a process use
-  // system calls such as openat() to bypass restrictions such as
-  // DropFileSystemAccess().
-  // Sometimes it's useful to call HasOpenDirectory() after file system access
-  // has been dropped. In this case, |proc_fd| should be a file descriptor to
-  // /proc. The file descriptor in |proc_fd| will be ignored by
-  // HasOpenDirectory() and remains owned by the caller. It is very important
-  // for the caller to close it.
-  // If /proc is available, |proc_fd| can be passed as -1.
-  // If |proc_fd| is -1 and /proc is not available, this function will return
-  // false.
-  bool HasOpenDirectory(int proc_fd);
-
   // Drop all capabilities in the effective, inheritable and permitted sets for
   // the current process.
   bool DropAllCapabilities();