Improve process launch handle sharing API.

chrome/browser/mac/relauncher.mm

 // Copyright 2012 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 "chrome/browser/mac/relauncher.h"
 
 #import <AppKit/AppKit.h>
 
 #include <AvailabilityMacros.h>
 #include <crt_externs.h>
@@ skipping 112 matching lines @@
   int pipe_fds[2];
   if (HANDLE_EINTR(pipe(pipe_fds)) != 0) {
     PLOG(ERROR) << "pipe";
     return false;
   }
 
   // The parent process will only use pipe_read_fd as the read side of the
   // pipe. It can close the write side as soon as the relauncher process has
   // forked off. The relauncher process will only use pipe_write_fd as the
   // write side of the pipe. In that process, the read side will be closed by
-  // base::LaunchApp because it won't be present in fd_map, and the write side
-  // will be remapped to kRelauncherSyncFD by fd_map.
+  // base::LaunchApp because it won't be present in fds_to_remap, and the write
+  // side will be remapped to kRelauncherSyncFD by fds_to_remap.
   base::ScopedFD pipe_read_fd(pipe_fds[0]);
   base::ScopedFD pipe_write_fd(pipe_fds[1]);
 
   // Make sure kRelauncherSyncFD is a safe value. base::LaunchProcess will
   // preserve these three FDs in forked processes, so kRelauncherSyncFD should
   // not conflict with them.
   static_assert(kRelauncherSyncFD != STDIN_FILENO &&
                 kRelauncherSyncFD != STDOUT_FILENO &&
                 kRelauncherSyncFD != STDERR_FILENO,
                 "kRelauncherSyncFD must not conflict with stdio fds");
 
-  base::FileHandleMappingVector fd_map;
-  fd_map.push_back(std::make_pair(pipe_write_fd.get(), kRelauncherSyncFD));
-
   base::LaunchOptions options;
-  options.fds_to_remap = &fd_map;
+  options.fds_to_remap.push_back(
+      std::make_pair(pipe_write_fd.get(), kRelauncherSyncFD));
   if (!base::LaunchProcess(relaunch_args, options).IsValid()) {
     LOG(ERROR) << "base::LaunchProcess failed";
     return false;
   }
 
   // The relauncher process is now starting up, or has started up. The
   // original parent process continues.
 
   pipe_write_fd.reset();  // close(pipe_fds[1]);
 
@@ skipping 206 matching lines @@
   if (!dmg_bsd_device_name.empty()) {
     EjectAndTrashDiskImage(dmg_bsd_device_name);
   }
 
   return 0;
 }
 
 }  // namespace internal
 
 }  // namespace mac_relauncher