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

chrome/browser/chrome_content_browser_client.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROME_CONTENT_BROWSER_CLIENT_H_
 #define CHROME_BROWSER_CHROME_CONTENT_BROWSER_CLIENT_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 253 matching lines @@
       int child_process_id,
       content::FileDescriptorInfo* mappings) override;
 #endif  // defined(OS_ANDROID)
 #if defined(OS_WIN)
   const wchar_t* GetResourceDllName() override;
   bool PreSpawnRenderer(sandbox::TargetPolicy* policy) override;
   base::string16 GetAppContainerSidForSandboxType(
       int sandbox_type) const override;
   bool IsWin32kLockdownEnabledForMimeType(
       const std::string& mime_type) const override;
-  bool ShouldUseWindowsPrefetchArgument() const override;
 #endif
   void RegisterRenderProcessMojoServices(
       content::ServiceRegistry* registry,
       content::RenderProcessHost* render_process_host) override;
   void RegisterFrameMojoShellServices(
       content::ServiceRegistry* registry,
       content::RenderFrameHost* render_frame_host) override;
   void RegisterRenderFrameMojoServices(
       content::ServiceRegistry* registry,
       content::RenderFrameHost* render_frame_host) override;
@@ skipping 57 matching lines @@
   // Vector of additional ChromeContentBrowserClientParts.
   // Parts are deleted in the reverse order they are added.
   std::vector<ChromeContentBrowserClientParts*> extra_parts_;
 
   base::WeakPtrFactory<ChromeContentBrowserClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeContentBrowserClient);
 };
 
 #endif  // CHROME_BROWSER_CHROME_CONTENT_BROWSER_CLIENT_H_