Small tweak to avoid pushing overlay URLs. This prevents overlays URLs from...

chrome/browser/resources/options/options_page.js

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 ///////////////////////////////////////////////////////////////////////////////
 // OptionsPage class:
 
 /**
  * Base class for options page.
  * @constructor
@@ skipping 128 matching lines @@
   },
 
   /**
    * Sets page visibility.
    */
   set visible(visible) {
     if ((this.visible && visible) || (!this.visible && !visible))
       return;
 
     if (visible) {
-      window.history.pushState({pageName: this.name},
-                               this.title,
-                               '/' + this.name);
       this.pageDiv.style.display = 'block';
       if (this.isOverlay) {
         var overlay = $('overlay');
         overlay.classList.remove('hidden');
+      } else {
+        window.history.pushState({pageName: this.name},
+                                 this.title,
+                                 '/' + this.name);
       }
       if (this.tab) {
         this.tab.classList.add('navbar-item-selected');
         if (this.tab.parentNode && this.tab.parentNode.id == 'subpagesnav')
           this.tab.classList.remove('hidden');
       }
     } else {
       if (this.isOverlay) {
         var overlay = $('overlay');
         overlay.classList.add('hidden');
       }
       this.pageDiv.style.display = 'none';
       if (this.tab) {
         this.tab.classList.remove('navbar-item-selected');
         if (this.tab.parentNode && this.tab.parentNode.id == 'subpagesnav')
           this.tab.classList.add('hidden');
       }
     }
 
     cr.dispatchPropertyChange(this, 'visible', visible, !visible);
   }
 };