Load user custom wallpaper after browser crash.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index aff6467325eb2904db942e38451b7df46ff6cb09..f255afb5225cc1a2d96876f7b8789f8dc5464391 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -239,8 +239,9 @@ class DummyUserWallpaperDelegate : public UserWallpaperDelegate {
 
   virtual ~DummyUserWallpaperDelegate() {}
 
-  virtual const int GetUserWallpaperIndex() OVERRIDE {
-    return -1;
+  virtual void SetLoggedInUserWallpaper() OVERRIDE {
+    ash::Shell::GetInstance()->desktop_background_controller()->
+        CreateEmptyWallpaper();
   }
 
   virtual void OpenSetWallpaperPage() OVERRIDE {
@@ -785,7 +786,7 @@ void Shell::Init() {
 
   // It needs to be created after OnWindowResized has been called, otherwise the
   // widget will not paint when restoring after a browser crash.
-  desktop_background_controller_->SetLoggedInUserWallpaper();
+  user_wallpaper_delegate_->SetLoggedInUserWallpaper();
 
   window_modality_controller_.reset(new internal::WindowModalityController);
   AddRootWindowEventFilter(window_modality_controller_.get());