Use a valid /prefetch argument when launching a process.

chrome/service/service_utility_process_host.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 "chrome/service/service_utility_process_host.h"
 
 #include <stdint.h>
 
 #include <queue>
 
@@ skipping 16 matching lines @@
 #include "content/public/common/content_switches.h"
 #include "content/public/common/result_codes.h"
 #include "content/public/common/sandbox_init.h"
 #include "content/public/common/sandboxed_process_launcher_delegate.h"
 #include "ipc/ipc_switches.h"
 #include "printing/emf_win.h"
 #include "sandbox/win/src/sandbox_policy.h"
 #include "sandbox/win/src/sandbox_types.h"
 #include "ui/base/ui_base_switches.h"
 
+#if defined(OS_WIN)
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
+#endif  // defined(OS_WIN)
+
 namespace {
 
 using content::ChildProcessHost;
 
 enum ServiceUtilityProcessHostEvent {
   SERVICE_UTILITY_STARTED,
   SERVICE_UTILITY_DISCONNECTED,
   SERVICE_UTILITY_METAFILE_REQUEST,
   SERVICE_UTILITY_METAFILE_SUCCEEDED,
   SERVICE_UTILITY_METAFILE_FAILED,
@@ skipping 171 matching lines @@
   if (exe_path.empty()) {
     NOTREACHED() << "Unable to get utility process binary name.";
     return false;
   }
 
   base::CommandLine cmd_line(exe_path);
   cmd_line.AppendSwitchASCII(switches::kProcessType, switches::kUtilityProcess);
   cmd_line.AppendSwitchASCII(switches::kProcessChannelID, channel_id);
   cmd_line.AppendSwitch(switches::kLang);
 
+#if defined(OS_WIN)
+  if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument)
+    cmd_line.AppendArg(switches::kPrefetchArgumentOther);
+#endif  // defined(OS_WIN)
+
   if (Launch(&cmd_line, no_sandbox)) {
     ReportUmaEvent(SERVICE_UTILITY_STARTED);
     return true;
   }
   ReportUmaEvent(SERVICE_UTILITY_FAILED_TO_START);
   return false;
 }
 
 bool ServiceUtilityProcessHost::Launch(base::CommandLine* cmd_line,
                                        bool no_sandbox) {
@@ skipping 181 matching lines @@
     return false;
   }
   printing::Emf emf;
   if (!emf.InitFromData(data.data(), data.size())) {
     OnRenderPDFPagesToMetafileDone(false);
     return false;
   }
   OnRenderPDFPagesToMetafilePageDone(scale_factor, emf);
   return true;
 }