Use PageManager in About page

chrome/browser/resources/options/browser_options.js

Index: chrome/browser/resources/options/browser_options.js
diff --git a/chrome/browser/resources/options/browser_options.js b/chrome/browser/resources/options/browser_options.js
index d55284ee2e51e383c1dd229ebaa8b9aa184b8f51..c984a08ae6639e7c23496557f83e48ccb6bf62f0 100644
--- a/chrome/browser/resources/options/browser_options.js
+++ b/chrome/browser/resources/options/browser_options.js
@@ -79,6 +79,12 @@ cr.define('options', function() {
       Page.prototype.initializePage.call(this);
       var self = this;
 
+      if (window.top != window) {
+        // The options page is not in its own window.
+        document.body.classList.add('uber-frame');
+        PageManager.horizontalOffset = 155;
+      }
+
       // Ensure that navigation events are unblocked on uber page. A reload of
       // the settings page while an overlay is open would otherwise leave uber
       // page in a blocked state, where tab switching is not possible.