Use a valid /prefetch argument when launching a process.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 67f45e6b5283db6f5e52aa1a2b163a2997742412..32f8edb5644e2ce64cf8377b6e20a0f1ad61b0c1 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -193,6 +193,7 @@
 #include "content/browser/renderer_host/dwrite_font_proxy_message_filter_win.h"
 #include "content/common/font_cache_dispatcher_win.h"
 #include "content/common/sandbox_win.h"
+#include "content/public/common/prefetch_argument_win.h"
 #include "sandbox/win/src/sandbox_policy.h"
 #include "ui/gfx/win/dpi.h"
 #endif
@@ -1291,6 +1292,10 @@ void RenderProcessHostImpl::AppendRendererCommandLine(
   command_line->AppendSwitchASCII(switches::kProcessType,
                                   switches::kRendererProcess);
 
+#if defined(OS_WIN)
+  AddWindowsPrefetchArgument(PREFETCH_ID_RENDERER, command_line);
+#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();