Handle the PasswordManagerAllowShowPasswords preference in the options webui.

chrome/browser/resources/options/password_manager_list.js

Index: chrome/browser/resources/options/password_manager_list.js
diff --git a/chrome/browser/resources/options/password_manager_list.js b/chrome/browser/resources/options/password_manager_list.js
index b286e8e610c04a97fc03e556f339755de64cb033..b15aace46c09d86ad3344a8296d39542536d6401 100644
--- a/chrome/browser/resources/options/password_manager_list.js
+++ b/chrome/browser/resources/options/password_manager_list.js
@@ -14,10 +14,11 @@ cr.define('options.passwordManager', function() {
    * @constructor
    * @extends {cr.ui.ListItem}
    */
-  function PasswordListItem(entry) {
+  function PasswordListItem(entry, showPassword) {
     var el = cr.doc.createElement('div');
     el.dataItem = entry;
     el.__proto__ = PasswordListItem.prototype;
+    el.showPassword = showPassword;
     el.decorate();
 
     return el;
@@ -57,18 +58,23 @@ cr.define('options.passwordManager', function() {
       passwordInputDiv.appendChild(passwordInput);
 
       // The show/hide button.
-      var button = this.ownerDocument.createElement('button');
-      button.classList.add('hidden');
-      button.classList.add('password-button');
-      button.textContent = localStrings.getString('passwordShowButton');
-      button.addEventListener('click', this.onClick_, true);
-      passwordInputDiv.appendChild(button);
+      if (this.showPassword) {
+        var button = this.ownerDocument.createElement('button');
+        button.classList.add('hidden');
+        button.classList.add('password-button');
+        button.textContent = localStrings.getString('passwordShowButton');
+        button.addEventListener('click', this.onClick_, true);
+        passwordInputDiv.appendChild(button);
+      }
 
       this.contentElement.appendChild(passwordInputDiv);
     },
 
     /** @inheritDoc */
     selectionChanged: function() {
+      if (!this.showPassword)
+        return;
+
       var passwordInput = this.querySelector('input[type=password]');
       var textInput = this.querySelector('input[type=text]');
       var input = passwordInput || textInput;
@@ -191,7 +197,7 @@ cr.define('options.passwordManager', function() {
 
     /** @inheritDoc */
     createItem: function(entry) {
-      return new PasswordListItem(entry);
+      return new PasswordListItem(entry, this.showPasswords);
     },
 
     /** @inheritDoc */
@@ -205,6 +211,12 @@ cr.define('options.passwordManager', function() {
     get length() {
       return this.dataModel.length;
     },
+
+    /**
+     * Whether passwords can be displayed in clear text or not.
+     * @type {boolean}
+     */
+    showPasswords: true,
   };
 
   /**