Wallpaper manager backend APIs

ash/desktop_background/desktop_background_resources.h

Index: ash/desktop_background/desktop_background_resources.h
diff --git a/ash/desktop_background/desktop_background_resources.h b/ash/desktop_background/desktop_background_resources.h
index 7c14ce6f94a8317ead5e62ed9a5148c4766b82c0..475c9bb2cde6d67e530ea1ffb156668dc9373758 100644
--- a/ash/desktop_background/desktop_background_resources.h
+++ b/ash/desktop_background/desktop_background_resources.h
@@ -5,6 +5,8 @@
 #ifndef ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_RESOURCES_H_
 #define ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_RESOURCES_H_
 
+#include <string>
+
 #include "ash/ash_export.h"
 #include "third_party/skia/include/core/SkColor.h"
 
@@ -32,6 +34,7 @@ const SkColor kLoginWallpaperColor = 0xFEFEFE;
 ASH_EXPORT int GetDefaultWallpaperIndex();
 ASH_EXPORT int GetGuestWallpaperIndex();
 ASH_EXPORT int GetInvalidWallpaperIndex();
+ASH_EXPORT WallpaperLayout GetLayoutEnum(const char* layout);
 ASH_EXPORT int GetNextWallpaperIndex(int index);
 ASH_EXPORT int GetSolidColorIndex();
 ASH_EXPORT int GetWallpaperCount();