Preload default wallpaper.

chrome/browser/chromeos/login/user_manager_impl.cc

Index: chrome/browser/chromeos/login/user_manager_impl.cc
diff --git a/chrome/browser/chromeos/login/user_manager_impl.cc b/chrome/browser/chromeos/login/user_manager_impl.cc
index 8aa31816ed2cdcb354e4259b2b529609ba6e0ff0..ec36d7bcfea1034730ede266f9cc8581d2ce1516 100644
--- a/chrome/browser/chromeos/login/user_manager_impl.cc
+++ b/chrome/browser/chromeos/login/user_manager_impl.cc
@@ -732,7 +732,7 @@ void UserManagerImpl::EnsureUsersLoaded() {
         User* user = CreateUser(email, /* is_ephemeral= */ false);
         users_.push_back(user);
 
-        WallpaperManager::Get()->CacheIfCustomWallpaper(email);
+        WallpaperManager::Get()->CacheUserWallpaper(email);

[Nikita (slow), 2012/08/03 18:09:39]

I've just realized that this place doesn't seem like a correct for this call.

EnsureUsersLoaded might be called multiple times per the existence of of
UserManager.

1. Cached should be executed only while at the login screen.
2. It should be executed exactly once.

[bshe, 2012/08/03 18:14:54]

I see. Where do you think is the best place to start the caching operations? It
will be heavy io operations if we have lots of user logged in. So we probably
want to only start these operations when IO is not busy.

On 2012/08/03 18:09:39, Nikita Kostylev wrote:

[Nikita (slow), 2012/08/03 18:21:31]

Correct. Now we have 2 ways how first user wallpaper might be loaded:

1. Loaded on boot, login WebUI waits for it. loadWallpaper is not called on
first user selection as it is already done.

Caching operation might be executed as a delayed task after it receives
NOTIFICATION_LOGIN_WEBUI_VISIBLE notification. See
http://code.google.com/codesearch#OAMlx_jo-ck/src/chrome/common/chrome_notifi...

2. Flag --disable-boot-animation is passed (might be the case on mario/alex/zgb
when I decide to add that flag).

Login WebUI is loaded right away.
First user gets preselected, in 500ms after that loadWallpaper is called.

In this case caching operation should be scheduled as a delayed one once it
completes.

 
         if (prefs_images) {
           // Get account image path.