Move AlterEnvironment to base/environment.h, implement on Windows.

base/process/launch.cc

+// Copyright (c) 2013 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"
+
+namespace base {
+
+LaunchOptions::LaunchOptions()
+    : wait(false),
+#if defined(OS_WIN)
+      start_hidden(false),
+      inherit_handles(false),
+      as_user(NULL),
+      empty_desktop_name(false),
+      job_handle(NULL),
+      stdin_handle(NULL),
+      stdout_handle(NULL),
+      stderr_handle(NULL),
+      force_breakaway_from_job_(false)
+#else
+      fds_to_remap(NULL),
+      maximize_rlimits(NULL),
+      new_process_group(false)
+#if defined(OS_LINUX)
+      , clone_flags(0)
+#endif  // OS_LINUX
+#if defined(OS_CHROMEOS)
+      , ctrl_terminal_fd(-1)
+#endif  // OS_CHROMEOS
+#endif  // !defined(OS_WIN)
+    {
+}
+
+LaunchOptions::~LaunchOptions() {
+}
+
+}  // namespace base