Improve process launch handle sharing API.

sandbox/linux/suid/client/setuid_sandbox_host.cc

 // 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.
 
 #include "sandbox/linux/suid/client/setuid_sandbox_host.h"
 
 #include <fcntl.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <sys/stat.h>
@@ skipping 147 matching lines @@
                   "configured correctly. Rather than run without sandboxing "
                   "I'm aborting now. You need to make sure that "
                << sandbox_binary << " is owned by root and has mode 4755.";
   }
 
   cmd_line->PrependWrapper(sandbox_binary);
 }
 
 void SetuidSandboxHost::SetupLaunchOptions(
     base::LaunchOptions* options,
-    base::FileHandleMappingVector* fds_to_remap,
     base::ScopedFD* dummy_fd) {
   DCHECK(options);
-  DCHECK(fds_to_remap);
 
   // Launching a setuid binary requires PR_SET_NO_NEW_PRIVS to not be used.
   options->allow_new_privs = true;
   UnsetExpectedEnvironmentVariables(&options->environ);
 
   // Set dummy_fd to the reading end of a closed pipe.
   int pipe_fds[2];
   PCHECK(0 == pipe(pipe_fds));
   PCHECK(0 == IGNORE_EINTR(close(pipe_fds[1])));
   dummy_fd->reset(pipe_fds[0]);
 
   // We no longer need a dummy socket for discovering the child's PID,
   // but the sandbox is still hard-coded to expect a file descriptor at
   // kZygoteIdFd. Fixing this requires a sandbox API change. :(
-  fds_to_remap->push_back(std::make_pair(dummy_fd->get(), kZygoteIdFd));
+  options->fds_to_remap.push_back(std::make_pair(dummy_fd->get(), kZygoteIdFd));
 }
 
 void SetuidSandboxHost::SetupLaunchEnvironment() {
   SaveSUIDUnsafeEnvironmentVariables(env_.get());
   SetSandboxAPIEnvironmentVariable(env_.get());
 }
 
 }  // namespace sandbox