Preload default wallpaper.

chrome/browser/chromeos/login/user_manager_impl.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 "chrome/browser/chromeos/login/user_manager_impl.h"
 
 #include <vector>
 
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/shell.h"
@@ skipping 714 matching lines @@
   int user_image_size = GetCurrentUserImageSize();
 
   if (prefs_users) {
     for (ListValue::const_iterator it = prefs_users->begin();
          it != prefs_users->end(); ++it) {
       std::string email;
       if ((*it)->GetAsString(&email)) {
         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.
           // TODO(avayvod): Reading image path as a string is here for
           // backward compatibility.
           std::string image_path;
           const base::DictionaryValue* image_properties;
           if (prefs_images->GetStringWithoutPathExpansion(email, &image_path)) {
             int image_id = User::kInvalidImageIndex;
             if (IsDefaultImagePath(image_path, &image_id)) {
@@ skipping 626 matching lines @@
     BrowserThread::PostTask(
         BrowserThread::FILE,
         FROM_HERE,
         base::Bind(&UserManagerImpl::DeleteUserImage,
                    base::Unretained(this),
                    image_path));
   }
 }
 
 }  // namespace chromeos