If customization includes default wallpaper, download and apply it.

chrome/browser/chromeos/customization_document.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_CUSTOMIZATION_DOCUMENT_H_
 #define CHROME_BROWSER_CHROMEOS_CUSTOMIZATION_DOCUMENT_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 25 matching lines @@
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 // This test is in global namespace so it must be declared here.
 void Test__InitStartupCustomizationDocument(const std::string& manifest);
 
 namespace chromeos {
 
 class ServicesCustomizationExternalLoader;
+class CustomizationWallpaperDownloader;
 
 namespace system {
 class StatisticsProvider;
 }  // system
 
 // Base class for OEM customization document classes.
 class CustomizationDocument {
  public:
   virtual ~CustomizationDocument();
 
@@ skipping 114 matching lines @@
   extensions::ExternalLoader* CreateExternalLoader(Profile* profile);
 
   // Returns the name of the folder for OEM apps for given |locale|.
   std::string GetOemAppsFolderName(const std::string& locale) const;
 
   // Set delay between network checking for testing.
   void SetZeroNetworkDelayForTesting() {
     network_delay_ = base::TimeDelta();
   }
 
+  // This is also used by WallpaperManager to set customized wallpaper path
+  // to global default before first wallpaper is shown.
+  static base::FilePath GetCustomizedWallpaperCacheDir();
+  static base::FilePath GetCustomizedWallpaperDownloadedFileName();
+
  private:
   friend struct DefaultSingletonTraits<ServicesCustomizationDocument>;
+  friend class CustomizationWallpaperDownloader;

[Dmitry Polukhin, 2014/03/27 04:36:32]

What exactly do you need from private interface of
ServicesCustomizationDocument? I would prefer to expand public interface in
controlled way instead of open impl part.

[Alexander Alekseev, 2014/03/31 14:15:40]

OnCustomizedWallpaperDownloaded();

Ok, let's make it public.

 
   typedef std::vector<base::WeakPtr<ServicesCustomizationExternalLoader> >
       ExternalLoaders;
 
   // C-tor for singleton construction.
   ServicesCustomizationDocument();
 
   // C-tor for test construction.
   explicit ServicesCustomizationDocument(const std::string& manifest);
 
@@ skipping 36 matching lines @@
   void OnCustomizationNotFound();
 
   // Set OEM apps folder name for AppListSyncableService for |profile|.
   void SetOemFolderName(Profile* profile, const base::DictionaryValue& root);
 
   // Returns the name of the folder for OEM apps for given |locale|.
   std::string GetOemAppsFolderNameImpl(
       const std::string& locale,
       const base::DictionaryValue& root) const;
 
+  // Set Shell default wallpaper to customized.
+  static void SetDefaultWallpaperPath(const GURL& wallpaper_url);

[Daniel Erat, 2014/03/27 01:45:50]

nit: SetDefaultWallpaperURL -- "Path" makes it sounds like it's a FilePath.

[Alexander Alekseev, 2014/03/31 14:15:40]

Done.

+
+  // This is called by CustomizationWallpaperDownloader to destroy self.
+  static void DestroyWallpaperDownloader();
+
+  // Start download of wallpaper image if need.
+  void StartOEMWallpaperDownload(const GURL& wallpaper_url);
+
+  // Check downloaded wallpaper and start download if needed.
+  void CheckAndApplyWallpaper();
+
+  // Intermediate function to pass the result of PathExists to ApplyWallpaper.
+  void OnCheckedWallpaperCacheExists(scoped_ptr<bool>);
+
+  // Called after downloaded wallpaper has been checked.
+  void ApplyWallpaper(bool default_wallpaper_file_exists);
+
   // Services customization manifest URL.
   GURL url_;
 
   // URLFetcher instance.
   scoped_ptr<net::URLFetcher> url_fetcher_;
 
   // How many times we already tried to fetch customization manifest file.
   int num_retries_;
 
   // Manifest fetch is already in progress.
   bool fetch_started_;
 
   // Delay between checks for network online state.
   base::TimeDelta network_delay_;
 
   // Known external loaders.
   ExternalLoaders external_loaders_;
 
   // Weak factory for callbacks.
   base::WeakPtrFactory<ServicesCustomizationDocument> weak_ptr_factory_;
 
+  scoped_ptr<CustomizationWallpaperDownloader> wallpaper_downloader_;
+
   DISALLOW_COPY_AND_ASSIGN(ServicesCustomizationDocument);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CUSTOMIZATION_DOCUMENT_H_