Always use a /prefetch:# switch when launching a process on Windows.

chrome/common/service_process_util.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/common/service_process_util.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 15 matching lines @@
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/cloud_devices/common/cloud_devices_switches.h"
 #include "components/network_session_configurator/switches.h"
 #include "components/version_info/version_info.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/common/content_switches.h"
 #include "google_apis/gaia/gaia_switches.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)
-
 #if !defined(OS_MACOSX)
 
 namespace {
 
 // This should be more than enough to hold a version string assuming each part
 // of the version string is an int64_t.
 const uint32_t kMaxVersionStringLength = 256;
 
 // The structure that gets written to shared memory.
 struct ServiceProcessSharedData {
@@ skipping 112 matching lines @@
 std::unique_ptr<base::CommandLine> CreateServiceProcessCommandLine() {
   base::FilePath exe_path;
   PathService::Get(content::CHILD_PROCESS_EXE, &exe_path);
   DCHECK(!exe_path.empty()) << "Unable to get service process binary name.";
   std::unique_ptr<base::CommandLine> command_line(
       new base::CommandLine(exe_path));
   command_line->AppendSwitchASCII(switches::kProcessType,
                                   switches::kServiceProcess);
 
 #if defined(OS_WIN)
-  if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument)
-    command_line->AppendArg(switches::kPrefetchArgumentOther);
+  command_line->AppendArg(switches::kPrefetchArgumentOther);
 #endif  // defined(OS_WIN)
 
   static const char* const kSwitchesToCopy[] = {
     switches::kCloudPrintSetupProxy,
     switches::kCloudPrintURL,
     switches::kCloudPrintXmppEndpoint,
 #if defined(OS_WIN)
     switches::kEnableCloudPrintXps,
 #endif
     switches::kEnableLogging,
@@ skipping 99 matching lines @@
   shared_data->service_process_pid = base::GetCurrentProcId();
   shared_mem_service_data_.reset(shared_mem_service_data.release());
   return true;
 }
 
 IPC::ChannelHandle ServiceProcessState::GetServiceProcessChannel() {
   return ::GetServiceProcessChannel();
 }
 
 #endif  // !OS_MACOSX