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

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 1277 matching lines @@
   gpu_data_manager->AppendRendererCommandLine(command_line);
 }
 
 void RenderProcessHostImpl::AppendRendererCommandLine(
     base::CommandLine* command_line) const {
   // Pass the process type first, so it shows first in process listings.
   command_line->AppendSwitchASCII(switches::kProcessType,
                                   switches::kRendererProcess);
 
 #if defined(OS_WIN)
-  if (GetContentClient()->browser()->ShouldUseWindowsPrefetchArgument())
-    command_line->AppendArg(switches::kPrefetchArgumentRenderer);
+  command_line->AppendArg(switches::kPrefetchArgumentRenderer);
 #endif  // defined(OS_WIN)
 
   // Now send any options from our own command line we want to propagate.
   const base::CommandLine& browser_command_line =
       *base::CommandLine::ForCurrentProcess();
   PropagateBrowserCommandLineToRenderer(browser_command_line, command_line);
 
   // Pass on the browser locale.
   const std::string locale =
       GetContentClient()->browser()->GetApplicationLocale();
@@ skipping 1501 matching lines @@
   LOG(ERROR) << "Terminating render process for bad Mojo message: " << error;
 
   // The ReceivedBadMessage call below will trigger a DumpWithoutCrashing. Alias
   // enough information here so that we can determine what the bad message was.
   base::debug::Alias(&error);
   bad_message::ReceivedBadMessage(process.get(),
                                   bad_message::RPH_MOJO_PROCESS_ERROR);
 }
 
 }  // namespace content