Remove use of index in wallpaper picker code and some refactor

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 23302c8bbffa2ee5d9614a2e261afed3125a045e..4d4a5be8b8ec3979bc6ce81e37812db4a5fe2e8f 100644
--- a/ash/desktop_background/desktop_background_controller.h
+++ b/ash/desktop_background/desktop_background_controller.h
@@ -6,7 +6,6 @@
 #define ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_CONTROLLER_H_
 
 #include "ash/ash_export.h"
-#include "ash/desktop_background/desktop_background_resources.h"
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ -24,6 +23,31 @@ class RootWindow;
 
 namespace ash {
 
+enum WallpaperLayout {
+  CENTER,

[sky, 2012/11/19 22:21:19]

For enums that exist in the ash namespace they need to be named more
specifically. Eg WALLPAPER_LAYOUT_CENTER and WALLPAPER_RESOLUTION_LARGE.

[bshe, 2012/11/20 00:33:59]

Done.

+  CENTER_CROPPED,
+  STRETCH,
+  TILE,
+};
+
+enum WallpaperResolution {
+  LARGE,
+  SMALL
+};
+
+const SkColor kLoginWallpaperColor = 0xFEFEFE;
+
+// Encapsulates wallpaper infomation needed by desktop background controller.
+struct ASH_EXPORT WallpaperInfo {
+  int idr;
+  WallpaperLayout layout;
+};
+
+ASH_EXPORT extern const WallpaperInfo kDefaultLargeWallpaper;
+ASH_EXPORT extern const WallpaperInfo kDefaultSmallWallpaper;
+ASH_EXPORT extern const WallpaperInfo kGuestLargeWallpaper;
+ASH_EXPORT extern const WallpaperInfo kGuestSmallWallpaper;
+
 // The width and height of small/large resolution wallpaper. When screen size is
 // smaller than |kSmallWallpaperMaxWidth| and |kSmallWallpaperMaxHeight|, the
 // small resolution wallpaper should be used. Otherwise, uses the large
@@ -64,21 +88,16 @@ class ASH_EXPORT DesktopBackgroundController : public aura::WindowObserver {
   // is no image, e.g. background is solid color.
   gfx::ImageSkia GetCurrentWallpaperImage();
 
+  // Gets the IDR of current wallpaper. Returns -1 if current wallpaper is not
+  // a builtin wallpaper.
+  int GetWallpaperIDR() const;
+
   // Initialize root window's background.
   void OnRootWindowAdded(aura::RootWindow* root_window);
 
-  // Loads default wallpaper at |index| asynchronously but does not set the
-  // loaded image to current wallpaper. Resource bundle will cache the loaded
-  // image.
-  void CacheDefaultWallpaper(int index);
-
-  // Loads default wallpaper at |index| asynchronously and sets to current
-  // wallpaper after loaded.
-  void SetDefaultWallpaper(int index);
-
-  // Forces to reload the current default wallpaper. A different resolution
-  // wallpaper maybe loaded.
-  void ReloadDefaultWallpaper();
+  // Loads builtin wallpaper asynchronously and sets to current wallpaper after
+  // loaded.
+  void SetDefaultWallpaper(WallpaperInfo info);

[sky, 2012/11/19 22:21:19]

const WallpaperInfo&

[bshe, 2012/11/20 00:33:59]

Done.

 
   // Sets the user selected custom wallpaper. Called when user selected a file
   // from file system or changed the layout of wallpaper.