MD Settings: Fix subpage visibility and add appearance page tests

chrome/browser/resources/settings/appearance_page/appearance_page.html

Index: chrome/browser/resources/settings/appearance_page/appearance_page.html
diff --git a/chrome/browser/resources/settings/appearance_page/appearance_page.html b/chrome/browser/resources/settings/appearance_page/appearance_page.html
index fcc30552e0f7c06a18b6a4641c156b9c1bab9162..591f78823d25c45f6a1c610686f5edb34a25be48 100644
--- a/chrome/browser/resources/settings/appearance_page/appearance_page.html
+++ b/chrome/browser/resources/settings/appearance_page/appearance_page.html
@@ -41,7 +41,7 @@
         focus-config="[[focusConfig_]]">
       <neon-animatable route-path="default">
 <if expr="chromeos">
-        <div class="settings-box first two-line" id="wallpaperButton"
+        <div class="settings-box first two-line" id="setWallpaper"
             on-tap="openWallpaperManager_" actionable
             hidden="[[!pageVisibility.setWallpaper]]">
           <div class="start">
@@ -54,11 +54,11 @@
               aria-label="$i18n{setWallpaper}"
               aria-describedby="wallpaperSecondary"></button>
         </div>
-        <div class="settings-box two-line"
+        <div id="setTheme" class="settings-box two-line"
             hidden="[[!pageVisibility.setTheme]]">
 </if>
 <if expr="not chromeos">
-        <div class="settings-box two-line first"
+        <div id="setTheme" class="settings-box two-line first"
             hidden="[[!pageVisibility.setTheme]]">
 </if>
           <a class="start two-line inherit-color no-outline" tabindex="-1"
@@ -104,7 +104,7 @@
           </div>
 </if>
         </div>
-        <div class="settings-box"
+        <div id="homeButton" class="settings-box"
             hidden="[[!pageVisibility.homeButton]]">
           <settings-toggle-button class="start" elide-label
               pref="{{prefs.browser.show_home_button}}"
@@ -144,7 +144,7 @@
             </settings-radio-group>
           </div>
         </template>
-        <div class="settings-box"
+        <div id="bookmarksBar" class="settings-box"
             hidden="[[!pageVisibility.bookmarksBar]]">
           <settings-toggle-button class="start"
               pref="{{prefs.bookmark_bar.show_on_all_tabs}}"