Update from https://crrev.com/312600

base/process/process.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_PROCESS_PROCESS_PROCESS_H_
 #define BASE_PROCESS_PROCESS_PROCESS_H_
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/move.h"
@@ skipping 99 matching lines @@
 
  private:
 #if defined(OS_WIN)
   bool is_current_process_;
   win::ScopedHandle process_;
 #else
   ProcessHandle process_;
 #endif
 };
 
-#if defined(OS_LINUX)
-// A wrapper for clone with fork-like behavior, meaning that it returns the
-// child's pid in the parent and 0 in the child. |flags|, |ptid|, and |ctid| are
-// as in the clone system call (the CLONE_VM flag is not supported).
-//
-// This function uses the libc clone wrapper (which updates libc's pid cache)
-// internally, so callers may expect things like getpid() to work correctly
-// after in both the child and parent. An exception is when this code is run
-// under Valgrind. Valgrind does not support the libc clone wrapper, so the libc
-// pid cache may be incorrect after this function is called under Valgrind.
-//
-// As with fork(), callers should be extremely careful when calling this while
-// multiple threads are running, since at the time the fork happened, the
-// threads could have been in any state (potentially holding locks, etc.).
-// Callers should most likely call execve() in the child soon after calling
-// this.
-BASE_EXPORT pid_t ForkWithFlags(unsigned long flags, pid_t* ptid, pid_t* ctid);
-#endif
-
 }  // namespace base
 
 #endif  // BASE_PROCESS_PROCESS_PROCESS_H_