[Extensions] Default-enable the toolbar redesign on trunk

chrome/browser/ui/toolbar/app_menu_model.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/toolbar/app_menu_model.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/command_line.h"
@@ skipping 862 matching lines @@
             base::UserMetricsAction("Signin_Impression_FromMenu"));
       }
     }
   }
   return menu_items_added;
 }
 
 void AppMenuModel::CreateActionToolbarOverflowMenu() {
   // We only add the extensions overflow container if there are any icons that
   // aren't shown in the main container.
-  // browser_->window() can return null during startup.
-  if (browser_->window() &&
+  // browser_->window() can return null during startup, and
+  // GetToolbarActionsBar() can be null in testing.
+  if (browser_->window() && browser_->window()->GetToolbarActionsBar() &&
       browser_->window()->GetToolbarActionsBar()->NeedsOverflow()) {
 #if defined(OS_MACOSX)
     // There's a bug in AppKit menus, where if a menu item with a custom view
     // (like the extensions overflow menu) is the first menu item, it is not
     // highlightable or keyboard-selectable.
     // Adding any menu item before it (even one which is never visible) prevents
     // it, so add a bogus item here that will always be hidden.
     AddItem(kEmptyMenuItemCommand, base::string16());
 #endif
     AddItem(IDC_EXTENSIONS_OVERFLOW_MENU, base::string16());
@@ skipping 45 matching lines @@
                        ->GetZoomPercent();
   }
   zoom_label_ = l10n_util::GetStringFUTF16(
       IDS_ZOOM_PERCENT, base::IntToString16(zoom_percent));
 }
 
 void AppMenuModel::OnZoomLevelChanged(
     const content::HostZoomMap::ZoomLevelChange& change) {
   UpdateZoomControls();
 }