MD Settings: Add Learn More button to the Passwords subpage

chrome/browser/resources/settings/privacy_page/privacy_page.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_vars_css.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout-classes.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="../clear_browsing_data_dialog/clear_browsing_data_dialog.html">
 <link rel="import" href="../controls/settings_toggle_button.html">
@@ skipping 17 matching lines @@
 <link rel="import" href="../site_settings_page/site_settings_page.html">
 
 <if expr="use_nss_certs">
 <link rel="import" href="../certificate_manager_page/certificate_manager_page.html">
 </if>
 <link rel="import" href="privacy_page_browser_proxy.html">
 
 <dom-module id="settings-privacy-page">
   <template>
     <style include="settings-shared">
-      button[is='paper-icon-button-light'].icon-help {
-        background-image: url(../images/help_outline.svg);
-      }
     </style>
     <template is="dom-if" if="[[showClearBrowsingDataDialog_]]" restamp>
       <settings-clear-browsing-data-dialog prefs="{{prefs}}"
           on-close="onDialogClosed_">
       </settings-clear-browsing-data-dialog>
     </template>
     <settings-animated-pages id="pages" section="privacy">
       <neon-animatable route-path="default">
         <div class="settings-box first">
           <p class="privacy-explanation">$i18nRaw{improveBrowsingExperience}</p>
@@ skipping 142 matching lines @@
             page-title="$i18n{manageCertificates}">
           <settings-certificate-manager-page>
           </settings-certificate-manager-page>
         </settings-subpage>
       </template>
 </if>
       <template is="dom-if" route-path="/content">
         <settings-subpage
             associated-control="[[$$('#site-settings-subpage-trigger')]]"
             id="site-settings"
-            page-title="[[siteSettingsPageTitle_()]]">
-          <button class="icon-help subpage-title-extra"
-              is="paper-icon-button-light" on-tap="onHelpTap_"></button>
+            page-title="[[siteSettingsPageTitle_()]]"
+            learn-more-url="$i18n{exceptionsLearnMoreURL}">
           <settings-site-settings-page></settings-site-settings-page>
         </settings-subpage>
       </template>
 
       <template is="dom-if" route-path="/content/all" no-search>
         <settings-subpage page-title="$i18n{siteSettingsCategoryAllSites}">
           <all-sites></all-sites>
         </settings-subpage>
       </template>
       <template is="dom-if" route-path="/content/automaticDownloads" no-search>
@@ skipping 227 matching lines @@
                 category="{{ContentSettingsTypes.PROTECTED_CONTENT}}">
             </category-setting-exceptions>
           </template>
 </if>
         </settings-subpage>
       </template>
     </settings-animated-pages>
   </template>
   <script src="privacy_page.js"></script>
 </dom-module>