Improve process launch handle sharing API.

base/process/launch_mac.cc

 // Copyright (c) 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 "base/process/launch.h"
 
 #include <crt_externs.h>
 #include <mach/mach.h>
 #include <spawn.h>
 #include <string.h>
@@ skipping 94 matching lines @@
     DPSXCHECK(posix_spawnattr_setpgroup(attr.get(), 0));
   }
   DPSXCHECK(posix_spawnattr_setflags(attr.get(), flags));
 
   PosixSpawnFileActions file_actions;
 
   // Process file descriptors for the child. By default, LaunchProcess will
   // open stdin to /dev/null and inherit stdout and stderr.
   bool inherit_stdout = true, inherit_stderr = true;
   bool null_stdin = true;
-  if (options.fds_to_remap) {
-    for (const auto& dup2_pair : *options.fds_to_remap) {
-      if (dup2_pair.second == STDIN_FILENO) {
-        null_stdin = false;
-      } else if (dup2_pair.second == STDOUT_FILENO) {
-        inherit_stdout = false;
-      } else if (dup2_pair.second == STDERR_FILENO) {
-        inherit_stderr = false;
-      }
+  for (const auto& dup2_pair : options.fds_to_remap) {
+    if (dup2_pair.second == STDIN_FILENO) {
+      null_stdin = false;
+    } else if (dup2_pair.second == STDOUT_FILENO) {
+      inherit_stdout = false;
+    } else if (dup2_pair.second == STDERR_FILENO) {
+      inherit_stderr = false;
+    }
 
-      if (dup2_pair.first == dup2_pair.second) {
-        file_actions.Inherit(dup2_pair.second);
-      } else {
-        file_actions.Dup2(dup2_pair.first, dup2_pair.second);
-      }
+    if (dup2_pair.first == dup2_pair.second) {
+      file_actions.Inherit(dup2_pair.second);
+    } else {
+      file_actions.Dup2(dup2_pair.first, dup2_pair.second);
     }
   }
 
   if (null_stdin) {
     file_actions.Open(STDIN_FILENO, "/dev/null", O_RDONLY);
   }
   if (inherit_stdout) {
     file_actions.Inherit(STDOUT_FILENO);
   }
   if (inherit_stderr) {
@@ skipping 33 matching lines @@
     // finish is the sort of thing ThreadRestrictions is trying to prevent.
     base::ThreadRestrictions::AssertIOAllowed();
     pid_t ret = HANDLE_EINTR(waitpid(pid, nullptr, 0));
     DPCHECK(ret > 0);
   }
 
   return Process(pid);
 }
 
 }  // namespace base