If customization includes default wallpaper, download and apply it.

chrome/browser/chromeos/customization_document.h

Index: chrome/browser/chromeos/customization_document.h
diff --git a/chrome/browser/chromeos/customization_document.h b/chrome/browser/chromeos/customization_document.h
index 95885fc9439d3f3996a4f40ac9bca19483d77fc1..916ef8b67e5193a50f38bce54612da75a88adb99 100644
--- a/chrome/browser/chromeos/customization_document.h
+++ b/chrome/browser/chromeos/customization_document.h
@@ -43,6 +43,7 @@ void Test__InitStartupCustomizationDocument(const std::string& manifest);
 namespace chromeos {
 
 class ServicesCustomizationExternalLoader;
+class CustomizationWallpaperDownloader;
 
 namespace system {
 class StatisticsProvider;
@@ -177,8 +178,14 @@ class ServicesCustomizationDocument : public CustomizationDocument,
     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;
@@ -235,6 +242,24 @@ class ServicesCustomizationDocument : public CustomizationDocument,
       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_;
 
@@ -256,6 +281,8 @@ class ServicesCustomizationDocument : public CustomizationDocument,
   // Weak factory for callbacks.
   base::WeakPtrFactory<ServicesCustomizationDocument> weak_ptr_factory_;
 
+  scoped_ptr<CustomizationWallpaperDownloader> wallpaper_downloader_;
+
   DISALLOW_COPY_AND_ASSIGN(ServicesCustomizationDocument);
 };