Use a valid /prefetch argument when launching a process.

cloud_print/service/win/chrome_launcher.cc

Index: cloud_print/service/win/chrome_launcher.cc
diff --git a/cloud_print/service/win/chrome_launcher.cc b/cloud_print/service/win/chrome_launcher.cc
index 5c9013aa9a098bf5d73a89cc32e1a15dcff36a53..d386342590134438ab4d952e6054103ff2805116 100644
--- a/cloud_print/service/win/chrome_launcher.cc
+++ b/cloud_print/service/win/chrome_launcher.cc
@@ -214,6 +214,10 @@ void ChromeLauncher::Run() {
       cmd.AppendSwitchPath(switches::kUserDataDir, user_data_);
       cmd.AppendSwitch(switches::kNoServiceAutorun);
 
+#if defined(OS_WIN)
+      cmd.AppendArg(switches::kPrefetchArgumentOther);
+#endif  // defined(OS_WIN)
+
       // Optional.
       cmd.AppendSwitch(switches::kDisableDefaultApps);
       cmd.AppendSwitch(switches::kDisableExtensions);