[Extensions] Don't allow chrome.browserAction.openPopup on popups

chrome/browser/extensions/api/extension_action/extension_action_api.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/extensions/api/extension_action/extension_action_api.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/lazy_instance.h"
@@ skipping 214 matching lines @@
   if (!extension_action)
     return false;
 
   if (extension_action->action_type() == ActionInfo::TYPE_PAGE &&
       !FeatureSwitch::extension_action_redesign()->IsEnabled()) {
     // We show page actions in the location bar unless the new toolbar is
     // enabled.
     return browser->window()->GetLocationBar()->ShowPageActionPopup(
         extension, grant_active_tab_permissions);
   }
-  return browser->window()->GetToolbarActionsBar()->ShowToolbarActionPopup(
-      extension->id(), grant_active_tab_permissions);
+  ToolbarActionsBar* toolbar_actions_bar =
+      browser->window()->GetToolbarActionsBar();
+  // ToolbarActionsBar could be null if, e.g., this is a popup window with no
+  // toolbar.
+  return toolbar_actions_bar &&
+         toolbar_actions_bar->ShowToolbarActionPopup(
+             extension->id(), grant_active_tab_permissions);
 }
 
 bool ExtensionActionAPI::PageActionWantsToRun(
     const Extension* extension,
     content::WebContents* web_contents) {
   ExtensionAction* page_action =
       ExtensionActionManager::Get(browser_context_)->GetPageAction(*extension);
   return page_action &&
          page_action->GetIsVisible(SessionTabHelper::IdForTab(web_contents));
 }
@@ skipping 436 matching lines @@
   if (host->extension_host_type() != VIEW_TYPE_EXTENSION_POPUP ||
       host->extension()->id() != extension_->id())
     return;
 
   SendResponse(true);
   response_sent_ = true;
   registrar_.RemoveAll();
 }
 
 }  // namespace extensions