[unified-consent] Fix a11y issues on syncSetup page

 - Nested controls are removed:
 The aria attributes of buttons inside <a> links are removed,
 so they won't be read twice by a screen reader.

 - Missing aria labels are added to radio buttons.

Bug: 853996
Change-Id: I9e009425c4d6cc0c03135856135fb830d96cf989
Reviewed-on: https://chromium-review.googlesource.com/1206810
Commit-Queue: Thomas Tangl <tangltom@chromium.org>
Reviewed-by: Scott Chen <scottchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589371}

chrome/browser/resources/settings/people_page/sync_page.html

@@ -410,8 +410,7 @@
               $i18n{personalizeGoogleServicesTitle}
             </div>
             <paper-icon-button-light actionable class="icon-external">
-              <button aria-label="$i18n{personalizeGoogleServicesTitle}">
-              </button>
+              <button></button>
             </paper-icon-button-light>
           </a>
 
@@ -422,7 +421,7 @@
               $i18n{manageSyncedDataTitle}
             </div>
             <paper-icon-button-light actionable class="icon-external">
-              <button aria-label="$i18n{manageSyncedDataTitle}"></button>
+              <button></button>
             </paper-icon-button-light>
           </a>
 
@@ -452,20 +451,29 @@
                 on-paper-radio-group-changed=
                     "onEncryptionRadioSelectionChanged_">
               <cr-radio-button name="encrypt-with-google"
-                  class="list-item" disabled="[[syncPrefs.encryptAllData]]">
+                  class="list-item" disabled="[[syncPrefs.encryptAllData]]"
+                  aria-label="$i18n{encryptWithGoogleCredentialsLabel}">
                 $i18n{encryptWithGoogleCredentialsLabel}
               </cr-radio-button>
-              <cr-radio-button name="encrypt-with-passphrase"
-                  class="list-item" disabled="[[syncPrefs.encryptAllData]]">
-                <template is="dom-if" if="[[syncPrefs.fullEncryptionBody]]">
-                  <span>[[syncPrefs.fullEncryptionBody]]</span>
-                </template>
-                <template is="dom-if" if="[[!syncPrefs.fullEncryptionBody]]">
-                  <span on-click="onLearnMoreTap_">
+              <template is="dom-if" if="[[syncPrefs.fullEncryptionBody]]">
+                <cr-radio-button name="encrypt-with-passphrase"
+                    class="list-item" disabled="[[syncPrefs.encryptAllData]]"
+                    aria-labelledby="fullEncryptionBody">
+                  <span id="fullEncryptionBody">
+                    [[syncPrefs.fullEncryptionBody]]
+                  </span>
+                </cr-radio-button>
+              </template>
+              <template is="dom-if" if="[[!syncPrefs.fullEncryptionBody]]">
+                <cr-radio-button name="encrypt-with-passphrase"
+                    class="list-item" disabled="[[syncPrefs.encryptAllData]]"
+                    aria-labelledby="encryptWithSyncPassphraseLabel">
+                  <span id="encryptWithSyncPassphraseLabel"
+                      on-click="onLearnMoreTap_">
                     $i18nRaw{encryptWithSyncPassphraseLabel}
                   </span>
-                </template>
-              </cr-radio-button>
+                </cr-radio-button>
+              </template>
             </paper-radio-group>
           </div>