Apply default wallpaper from customization manifest.

ash/desktop_background/desktop_background_controller.h

Index: ash/desktop_background/desktop_background_controller.h
diff --git a/ash/desktop_background/desktop_background_controller.h b/ash/desktop_background/desktop_background_controller.h
index b1099c619f75f30bf21b60536d9e5c552567f318..8d9f698b8f8e816e124e280961a6dc1db7ee6774 100644
--- a/ash/desktop_background/desktop_background_controller.h
+++ b/ash/desktop_background/desktop_background_controller.h
@@ -37,7 +37,7 @@ enum WallpaperLayout {
   // desktop's size.
   WALLPAPER_LAYOUT_STRETCH,
   // Tile the wallpaper over the background without scaling it.
-  WALLPAPER_LAYOUT_TILE,
+  WALLPAPER_LAYOUT_TILE
 };
 
 const SkColor kLoginWallpaperColor = 0xFEFEFE;
@@ -57,6 +57,10 @@ class ASH_EXPORT DesktopBackgroundController
     BACKGROUND_IMAGE,
   };
 
+  // This is used to initialize Resource ID variables and to denote "no
+  // resource ID" in parameters.
+  static const int kInvalidResourceID;
+
   DesktopBackgroundController();
   virtual ~DesktopBackgroundController();
 
@@ -110,18 +114,20 @@ class ASH_EXPORT DesktopBackgroundController
   // maximum width of all displays, and the maximum height of all displays.
   static gfx::Size GetMaxDisplaySizeInNative();
 
- private:
-  friend class DesktopBackgroundControllerTest;
-  //  friend class chromeos::WallpaperManagerBrowserTestDefaultWallpaper;
-  FRIEND_TEST_ALL_PREFIXES(DesktopBackgroundControllerTest, GetMaxDisplaySize);
-
   // Returns true if the specified wallpaper is already stored
   // in |current_wallpaper_|.
   // If |image| is NULL, resource_id is compared.
+  // If |compare_layouts| is false, layout is ignored.
   bool WallpaperIsAlreadyLoaded(const gfx::ImageSkia* image,
                                 int resource_id,
+                                bool compare_layouts,
                                 WallpaperLayout layout) const;
 
+ private:
+  friend class DesktopBackgroundControllerTest;
+  //  friend class chromeos::WallpaperManagerBrowserTestDefaultWallpaper;
+  FRIEND_TEST_ALL_PREFIXES(DesktopBackgroundControllerTest, GetMaxDisplaySize);
+
   // Creates view for all root windows, or notifies them to repaint if they
   // already exist.
   void SetDesktopBackgroundImageMode();