Revert r207560 and r207566 to reland r207511.

ash/ash_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 "ash/ash_switches.h"
 
 #include "base/command_line.h"
 
 namespace ash {
 namespace switches {
@@ skipping 11 matching lines @@
 
 // Copies the host window's content to the system background layer at startup.
 // Can make boot slightly slower, but also hides an even-longer awkward period
 // where we display a white background if the login wallpaper takes a long time
 // to load.
 const char kAshCopyHostBackgroundAtBoot[] = "ash-copy-host-background-at-boot";
 
 // Enable keyboard shortcuts useful for debugging.
 const char kAshDebugShortcuts[] = "ash-debug-shortcuts";
 
+// Default wallpaper to use in guest mode (as paths to trusted,
+// non-user-writable JPEG files).
+const char kAshDefaultGuestWallpaperLarge[] =
+    "ash-default-guest-wallpaper-large";
+const char kAshDefaultGuestWallpaperSmall[] =
+    "ash-default-guest-wallpaper-small";
+
+// Default wallpaper to use (as paths to trusted, non-user-writable JPEG files).
+const char kAshDefaultWallpaperLarge[] = "ash-default-wallpaper-large";
+const char kAshDefaultWallpaperSmall[] = "ash-default-wallpaper-small";
+
 // Disable auto window maximization logic.
 const char kAshDisableAutoMaximizing[] = "ash-disable-auto-maximizing";
 
 // Disable support for auto window placement.
 const char kAshDisableAutoWindowPlacement[] =
     "ash-enable-auto-window-placement";
 
 // Disables the limitter to throttle how quickly a user
 // can change display settings.
 const char kAshDisableDisplayChangeLimiter[] =
@@ skipping 131 matching lines @@
           HasSwitch(ash::switches::kAshEnableAudioDeviceMenu);
 }
 
 bool UseAlternateShelfLayout() {
   return CommandLine::ForCurrentProcess()->
         HasSwitch(ash::switches::kAshUseAlternateShelfLayout);
 }
 
 }  // namespace switches
 }  // namespace ash