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

chrome/browser/resources/options2/browser_options.html

Index: chrome/browser/resources/options2/browser_options.html
diff --git a/chrome/browser/resources/options2/browser_options.html b/chrome/browser/resources/options2/browser_options.html
index ded931ff002fcba573abfdfe7012bf4a849ce530..466a97c2ec59467c7c48c56e591ffdbb5c78290c 100644
--- a/chrome/browser/resources/options2/browser_options.html
+++ b/chrome/browser/resources/options2/browser_options.html
@@ -89,21 +89,22 @@
 </if>
   <section>
     <h3 i18n-content="sectionTitleAppearance"></h3>
-<if expr="not pp_ifdef('toolkit_views') and is_posix and not is_macosx">
     <div>
+<if expr="pp_ifdef('use_ash')">
+      <button id="set-wallpaper" i18n-content="setWallpaper"></button>
+</if>
+<if expr="not pp_ifdef('toolkit_views') and is_posix and not is_macosx">
       <button id="themes-gallery" i18n-content="themesGallery"></button>
       <button id="themes-GTK-button"
           i18n-content="themesGTKButton"></button>
       <button id="themes-reset"
           i18n-content="themesSetClassic"></button>
-    </div>
 </if>
 <if expr="pp_ifdef('toolkit_views') or is_win or is_macosx">
-    <div>
       <button id="themes-gallery" i18n-content="themesGallery"></button>
       <button id="themes-reset" i18n-content="themesReset"></button>
-    </div>
 </if>
+    </div>
     <div class="settings-row">
       <span i18n-content="homePage"></span>
       <select id="home-page-select">