Add comments and fix a potential leak in LaunchProcess.

base/process_util.h

 // 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.
 
 // This file/namespace contains utility functions for enumerating, ending and
 // computing statistics of processes.
 
 #ifndef BASE_PROCESS_UTIL_H_
 #define BASE_PROCESS_UTIL_H_
 #pragma once
@@ skipping 241 matching lines @@
   // the token belonging to an interactive logon session.
   //
   // To avoid hard to diagnose problems, when specified this loads the
   // environment variables associated with the user and if this operation fails
   // the entire call fails as well.
   UserTokenHandle as_user;
 
   // If true, use an empty string for the desktop name.
   bool empty_desktop_name;
 
-  // If non-NULL, launches the application in that job object.
+  // If non-NULL, launches the application in that job object. The process will
+  // be terminated immediately and LaunchProcess() will fail if assignment to
+  // the job object fails.
   HANDLE job_handle;
 #else
   // If non-NULL, set/unset environment variables.
   // See documentation of AlterEnvironment().
   // This pointer is owned by the caller and must live through the
   // call to LaunchProcess().
   const EnvironmentVector* environ;
 
   // If non-NULL, remap file descriptors according to the mapping of
   // src fd->dest fd to propagate FDs into the child process.
@@ skipping 42 matching lines @@
   // |synchronize| and |wait| must not both be set simultaneously.
   LaunchSynchronizationHandle* synchronize;
 #endif  // defined(OS_MACOSX)
 
 #endif  // !defined(OS_WIN)
 };
 
 // Launch a process via the command line |cmdline|.
 // See the documentation of LaunchOptions for details on |options|.
 //
-// If |process_handle| is non-NULL, it will be filled in with the
+// Returns true upon success.
+//
+// Upon success, if |process_handle| is non-NULL, it will be filled in with the
 // handle of the launched process.  NOTE: In this case, the caller is
 // responsible for closing the handle so that it doesn't leak!
 // Otherwise, the process handle will be implicitly closed.
 //
 // Unix-specific notes:
 // - All file descriptors open in the parent process will be closed in the
 //   child process except for any preserved by options::fds_to_remap, and
 //   stdin, stdout, and stderr. If not remapped by options::fds_to_remap,
 //   stdin is reopened as /dev/null, and the child is allowed to inherit its
 //   parent's stdout and stderr.
@@ skipping 491 matching lines @@
 // instance running inside the parent.  The parent's Breakpad instance should
 // not handle the child's exceptions.  Calling RestoreDefaultExceptionHandler
 // in the child after forking will restore the standard exception handler.
 // See http://crbug.com/20371/ for more details.
 void RestoreDefaultExceptionHandler();
 #endif  // defined(OS_MACOSX)
 
 }  // namespace base
 
 #endif  // BASE_PROCESS_UTIL_H_