ChromeOS OOBE: More accessibility fixes.

chrome/browser/resources/chromeos/login/oobe_welcome.html

Index: chrome/browser/resources/chromeos/login/oobe_welcome.html
diff --git a/chrome/browser/resources/chromeos/login/oobe_welcome.html b/chrome/browser/resources/chromeos/login/oobe_welcome.html
index 52ff0bb504cbaa948ceae29d8183f362ca53eeea..cd5cde6f2b92c706ea11b4a2c996c935d60c2d04 100644
--- a/chrome/browser/resources/chromeos/login/oobe_welcome.html
+++ b/chrome/browser/resources/chromeos/login/oobe_welcome.html
@@ -58,7 +58,7 @@
     <link rel="stylesheet" href="oobe_welcome.css">
     <link rel="stylesheet" href="oobe_dialog_parameters.css">
     <oobe-welcome-dialog id="welcomeScreen" role="dialog"
-        aria-label="[[formatMessage_('networkScreenGreeting')]]"
+        aria-label$="[[formatMessage_('networkScreenGreeting')]]"
         current-language="[[currentLanguage]]"
         on-language-button-clicked="onWelcomeSelectLanguageButtonClicked_"
         on-accessibility-button-clicked="onWelcomeAccessibilityButtonClicked_"
@@ -69,7 +69,7 @@
         >
     </oobe-welcome-dialog>
     <oobe-dialog id="languageScreen" role="dialog" hidden has-buttons
-        aria-label="[[formatMessage_('languageSectionTitle')]]">
+        aria-label$="[[formatMessage_('languageSectionTitle')]]">
       <iron-icon icon="icons:language" class="oobe-icon"></iron-icon>
       <div class="header">
         <h1 class="title" i18n-content="languageSectionTitle"></h1>
@@ -83,7 +83,8 @@
             </div>
             <oobe-i18n-dropdown id="languageSelect" items="[[languages]]"
                 on-select-item="onLanguageSelected_"
-                class="focus-on-show">
+                class="focus-on-show"
+                label-for-aria="[[formatMessage_('languageDropdownLabel')]]">
             </oobe-i18n-dropdown>
           </div>
           <div id="keyboardDropdownContainer"
@@ -92,7 +93,8 @@
                 i18n-content="keyboardDropdownTitle">
             </div>
             <oobe-i18n-dropdown id="keyboardSelect" items="[[keyboards]]"
-                on-select-item="onKeyboardSelected_">
+                on-select-item="onKeyboardSelected_"
+                label-for-aria="[[formatMessage_('keyboardDropdownLabel')]]">
             </oobe-i18n-dropdown>
           </div>
         </template>
@@ -104,7 +106,7 @@
       </div>
     </oobe-dialog>
     <oobe-dialog id="accessibilityScreen" role="dialog" hidden has-buttons
-        aria-label="[[formatMessage_('accessibilitySectionTitle')]]">
+        aria-label$="[[formatMessage_('accessibilitySectionTitle')]]">
       <iron-icon icon="icons:accessibility" class="oobe-icon"></iron-icon>
       <div class="header">
         <h1 class="title" i18n-content="accessibilitySectionTitle"></h1>
@@ -170,7 +172,7 @@
       </div>
     </oobe-dialog>
     <oobe-dialog id="timezoneScreen" role="dialog" hidden has-buttons
-        aria-label="[[formatMessage_('timezoneSectionTitle')]]">
+        aria-label$="[[formatMessage_('timezoneSectionTitle')]]">
       <iron-icon icon="oobe-welcome-64:timezone" class="oobe-icon"></iron-icon>
       <div class="header">
         <h1 class="title" i18n-content="timezoneSectionTitle"></h1>
@@ -182,7 +184,7 @@
           </div>
           <oobe-i18n-dropdown id="timezoneSelect" items="[[timezones]]"
               on-select-item="onTimezoneSelected_"
-              label-for-aria="[[formatMessage_('timezoneDropdownTitle')]]"
+              label-for-aria="[[formatMessage_('timezoneDropdownLabel')]]"
               class="focus-on-show">
           </oobe-i18n-dropdown>
         </div>
@@ -194,7 +196,7 @@
       </div>
     </oobe-dialog>
     <oobe-dialog id="networkSelectionScreen" role="dialog" hidden has-buttons
-        aria-label="[[formatMessage_('networkSectionTitle')]]"
+        aria-label$="[[formatMessage_('networkSectionTitle')]]"
         on-show-dialog="onNetworkSelectionScreenShown_">
       <iron-icon icon="oobe-welcome:wifi" class="oobe-icon"></iron-icon>
       <div class="header">