Allow using the namespace sandbox in zygote host.

sandbox/linux/services/namespace_sandbox.h

 // Copyright 2015 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 SANDBOX_LINUX_SERVICES_NAMESPACE_SANDBOX_H_
 #define SANDBOX_LINUX_SERVICES_NAMESPACE_SANDBOX_H_
 
+#include <string>
+#include <vector>
+
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/process/launch.h"
 #include "base/process/process.h"
 #include "sandbox/sandbox_export.h"
 
 namespace sandbox {
 
 // Helper class for starting a process inside a new user, PID, and network
 // namespace. Before using a namespace sandbox, check for namespaces support
@@ skipping 16 matching lines @@
  public:
   // Launch a new process inside its own user/PID/network namespaces (depending
   // on kernel support). Requires at a minimum that user namespaces are
   // supported (use Credentials::CanCreateProcessInNewUserNS to check this).
   //
   // pre_exec_delegate and clone_flags fields of LaunchOptions should be nullptr
   // and 0, respectively, since this function makes a copy of options and
   // overrides them.
   static base::Process LaunchProcess(const base::CommandLine& cmdline,
                                      const base::LaunchOptions& options);
+  static base::Process LaunchProcess(const std::vector<std::string>& argv,
+                                     const base::LaunchOptions& options);
 
   // Returns whether the namespace sandbox created a new user, PID, and network
   // namespace. In particular, InNewUserNamespace should return true iff the
   // process was started via this class.
   static bool InNewUserNamespace();
   static bool InNewPidNamespace();
   static bool InNewNetNamespace();
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(NamespaceSandbox);
 };
 
 }  // namespace sandbox
 
 #endif  // SANDBOX_LINUX_SERVICES_NAMESPACE_SANDBOX_H_