If customization includes default wallpaper, download and apply it.

chrome/browser/ui/ash/chrome_shell_delegate.cc

Index: chrome/browser/ui/ash/chrome_shell_delegate.cc
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate.cc b/chrome/browser/ui/ash/chrome_shell_delegate.cc
index b425e44f02d1535bad2dff79e9b7c9f9f85c57f5..701936f90821d124c1ba09093ab59af89e0394ba 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.cc
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.cc
@@ -31,6 +31,7 @@
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #include "chrome/browser/chromeos/display/display_configuration_observer.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
+#include "chrome/browser/chromeos/login/wallpaper_manager.h"
 #endif
 
 // static
@@ -153,3 +154,33 @@ keyboard::KeyboardControllerProxy*
     ChromeShellDelegate::CreateKeyboardControllerProxy() {
   return new AshKeyboardControllerProxy();
 }
+
+bool ChromeShellDelegate::ShouldUseCustomizedDefaultWallpaper() const {
+#if defined(OS_CHROMEOS)
+  return chromeos::WallpaperManager::ShouldUseCustomizedDefaultWallpaper();
+#else
+  return false;
+#endif
+}
+
+base::FilePath
+ChromeShellDelegate::GetCustomizedWallpaperDefaultRescaledSmallFileName()
+    const {
+#if defined(OS_CHROMEOS)
+  return chromeos::WallpaperManager::
+      GetCustomizedWallpaperDefaultRescaledSmallFileName();
+#else
+  return base::FilePath();
+#endif
+}
+
+base::FilePath
+ChromeShellDelegate::GetCustomizedWallpaperDefaultRescaledLargeFileName()
+    const {
+#if defined(OS_CHROMEOS)
+  return chromeos::WallpaperManager::
+      GetCustomizedWallpaperDefaultRescaledLargeFileName();
+#else
+  return base::FilePath();
+#endif
+}