Enable user change background image in settings page in Aura build.

chrome/browser/resources/options2/options.js

Index: chrome/browser/resources/options2/options.js
diff --git a/chrome/browser/resources/options2/options.js b/chrome/browser/resources/options2/options.js
index 5dc7ff42cb4ff5973cd2ed20f1ca2a5e1c1b196b..17c24c3db44f76a27dd8da3c941cc47e43dc2c1c 100644
--- a/chrome/browser/resources/options2/options.js
+++ b/chrome/browser/resources/options2/options.js
@@ -164,6 +164,13 @@ function load() {
                                   LanguageOptions.getInstance());
     }
   }
+
+  if (SetWallpaperOptions) {
+    OptionsPage.registerOverlay(SetWallpaperOptions.getInstance(),
+                                BrowserOptions.getInstance(),
+                                [$('set-wallpaper')]);
+  }
+
   if (!cr.isWindows && !cr.isMac) {
     OptionsPage.registerOverlay(CertificateBackupOverlay.getInstance(),
                                 CertificateManager.getInstance());