MD Settings: label and describe a bunch of subpage/open-in-new buttons

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

 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/md_select_css.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="appearance_browser_proxy.html">
 <link rel="import" href="../controls/controlled_radio_button.html">
 <link rel="import" href="../controls/extension_controlled_indicator.html">
@@ skipping 23 matching lines @@
       }
     </style>
     <settings-animated-pages id="pages" section="appearance">
       <neon-animatable route-path="default">
 <if expr="chromeos">
         <div class="settings-box first two-line" id="wallpaperButton"
             on-tap="openWallpaperManager_" actionable
             hidden="[[!pageVisibility.setWallpaper]]">
           <div class="start">
             $i18n{setWallpaper}
-            <div class="secondary">$i18n{openWallpaperApp}</div>
+            <div class="secondary" id="wallpaperSecondary">
+              $i18n{openWallpaperApp}
+            </div>
           </div>
-          <button class="icon-external" is="paper-icon-button-light"></button>
+          <button class="icon-external" is="paper-icon-button-light"
+              aria-label="$i18n{setWallpaper}"
+              aria-describedby="wallpaperSecondary"></button>
         </div>
         <div class="settings-box two-line"
             hidden="[[!pageVisibility.setTheme]]">
 </if>
 <if expr="not chromeos">
         <div class="settings-box two-line first"
             hidden="[[!pageVisibility.setTheme]]">
 </if>
           <div class="start two-line" on-tap="onThemesTap_" actionable>
             <div class="flex">
-              <div>$i18n{themes}</div>
-              <div class="secondary">[[themeSublabel_]]</div>
+              $i18n{themes}
+              <div class="secondary" id="themesSecondary">
+                [[themeSublabel_]]
+              </div>
             </div>
-            <button class="icon-external" is="paper-icon-button-light"></button>
+            <button class="icon-external" is="paper-icon-button-light"
+                aria-label="$i18n{themes}"
+                aria-describedby="themesSecondary"></button>
           </div>
 <if expr="not is_linux or chromeos">
           <template is="dom-if" if="[[prefs.extensions.theme.id.value]]">
             <div class="secondary-action">
               <paper-button id="useDefault" on-tap="onUseDefaultTap_"
                   class="secondary-button">
                 $i18n{resetToDefaultTheme}
               </paper-button>
             </div>
           </template>
@@ skipping 78 matching lines @@
 </if>
           <div class="start">$i18n{fontSize}</div>
           <settings-dropdown-menu id="defaultFontSize"
               pref="{{prefs.webkit.webprefs.default_font_size}}"
               menu-options="[[fontSizeOptions_]]">
           </settings-dropdown-menu>
         </div>
         <div id="customize-fonts-subpage-trigger" class="settings-box two-line"
             on-tap="onCustomizeFontsTap_" actionable>
           <div class="start">
-            <div>$i18n{customizeFonts}</div>
-            <div class="secondary">$i18n{chooseFonts}</div>
+            $i18n{customizeFonts}
+            <div class="secondary" id="fontsSecondary">$i18n{chooseFonts}</div>
           </div>
-          <button class="subpage-arrow" is="paper-icon-button-light"></button>
+          <button class="subpage-arrow" is="paper-icon-button-light"
+              aria-label="$i18n{customizeFonts}"
+              aria-describedby="fontsSecondary"></button>
         </div>
         <div class="settings-box"
             hidden="[[!pageVisibility.pageZoom]]">
           <div class="start">$i18n{pageZoom}</div>
           <div class="md-select-wrapper">
             <select id="zoomLevel" class="md-select"
                 on-change="onZoomLevelChange_">
               <template is="dom-repeat" items="[[pageZoomLevels_]]">
                 <option value="[[item]]"
                     selected$="[[zoomValuesEqual_(item, defaultZoom_)]]">
@@ skipping 10 matching lines @@
             associated-control="[[$$('#customize-fonts-subpage-trigger')]]"
             page-title="$i18n{customizeFonts}">
           <settings-appearance-fonts-page prefs="{{prefs}}">
           </settings-appearance-fonts-page>
         </settings-subpage>
       </template>
     </settings-animated-pages>
   </template>
   <script src="appearance_page.js"></script>
 </dom-module>