Preload default wallpaper.

ash/desktop_background/desktop_background_controller.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/desktop_background/desktop_background_controller.h"
 
 #include "ash/desktop_background/desktop_background_view.h"
 #include "ash/shell.h"
 #include "ash/shell_factory.h"
 #include "ash/shell_window_ids.h"
@@ skipping 116 matching lines @@
       } else {
         internal::CreateDesktopBackground(root_window);
       }
       break;
     case BACKGROUND_SOLID_COLOR:
       SetDesktopBackgroundSolidColorMode(background_color_);
       break;
   }
 }
 
+void DesktopBackgroundController::TriggerCacheDefaultWallpaper(int index) {
+  if (index == ash::GetInvalidWallpaperIndex() ||

[Nikita (slow), 2012/08/06 16:36:01]

just check for index < 0 ?

[bshe, 2012/08/07 15:18:57]

I was trying to avoid magic number like 0. But i am fine either way. So using <
0.

On 2012/08/06 16:36:01, Nikita Kostylev wrote:

+      index == ash::GetSolidColorIndex())
+    return;
+  scoped_refptr<WallpaperOperation> wallpaper_op =
+      new WallpaperOperation(index);
+  base::WorkerPool::PostTask(
+      FROM_HERE,
+      base::Bind(&WallpaperOperation::Run, wallpaper_op),
+      true);
+}
+
 void DesktopBackgroundController::SetDefaultWallpaper(int index) {
   // We should not change background when index is invalid. For instance, at
   // login screen or stub_user login.
   if (index == ash::GetInvalidWallpaperIndex()) {
     CreateEmptyWallpaper();
     return;
   } else if (index == ash::GetSolidColorIndex()) {
     SetDesktopBackgroundSolidColorMode(kLoginWallpaperColor);
     return;
   }
@@ skipping 88 matching lines @@
   current_wallpaper_.reset(NULL);
   desktop_background_mode_ = BACKGROUND_IMAGE;
   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
   for (Shell::RootWindowList::iterator iter = root_windows.begin();
        iter != root_windows.end(); ++iter) {
     internal::CreateDesktopBackground(*iter);
   }
 }
 
 }  // namespace ash