[Extensions] Default-enable the toolbar redesign on trunk

chrome/browser/ui/toolbar/app_menu_model.cc

Index: chrome/browser/ui/toolbar/app_menu_model.cc
diff --git a/chrome/browser/ui/toolbar/app_menu_model.cc b/chrome/browser/ui/toolbar/app_menu_model.cc
index 62db93dd80592e787a69d4ca35052bbb17c9a0b0..07038112691ad15417dad0b758abe9942e11209e 100644
--- a/chrome/browser/ui/toolbar/app_menu_model.cc
+++ b/chrome/browser/ui/toolbar/app_menu_model.cc
@@ -880,8 +880,9 @@ bool AppMenuModel::AddGlobalErrorMenuItems() {
 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