Use a valid /prefetch argument when launching a process.

chrome/common/chrome_switches.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/chrome_switches.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "build/build_config.h"
 
@@ skipping 1239 matching lines @@
 const char kEnableProfileShortcutManager[]  = "enable-profile-shortcut-manager";
 
 // For the DelegateExecute verb handler to launch Chrome in metro mode on
 // Windows 8 and higher.  Used when relaunching metro Chrome.
 const char kForceImmersive[]                = "force-immersive";
 
 // Whether or not the browser should warn if the profile is on a network share.
 // This flag is only relevant for Windows currently.
 const char kNoNetworkProfileWarning[]       = "no-network-profile-warning";
 
+// /prefetch:# arguments for the browser process launched in background mode and
+// for the watcher process. These constants must be different from the
+// kPrefetchArgument* constants defined in content_switches.cc.

[gab, 2016/01/29 19:39:28]

s/These constants must.../Use profiles 6 and 7 as documented on
kPrefetchArgument* in content_switches.cc./

[fdoray, 2016/02/01 13:28:26]

Done.

+const char kPrefetchArgumentBrowserBackground[] = "/prefetch:6";
+const char kPrefetchArgumentWatcher[] = "/prefetch:7";
+
 // For the DelegateExecute verb handler to launch Chrome in desktop mode on
 // Windows 8 and higher.  Used when relaunching metro Chrome.
 const char kForceDesktop[]                  = "force-desktop";
 
 // Makes Windows happy by allowing it to show "Enable access to this program"
 // checkbox in Add/Remove Programs->Set Program Access and Defaults. This only
 // shows an error box because the only way to hide Chrome is by uninstalling
 // it.
 const char kHideIcons[]                     = "hide-icons";
 
@@ skipping 126 matching lines @@
 
 // -----------------------------------------------------------------------------
 // DO NOT ADD YOUR CRAP TO THE BOTTOM OF THIS FILE.
 //
 // You were going to just dump your switches here, weren't you? Instead, please
 // put them in alphabetical order above, or in order inside the appropriate
 // ifdef at the bottom. The order should match the header.
 // -----------------------------------------------------------------------------
 
 }  // namespace switches