[Extensions] Clean up renderer channel-related code

extensions/shell/test/shell_test.h

 // Copyright 2014 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.
 
 #ifndef EXTENSIONS_SHELL_TEST_SHELL_TEST_H_
 #define EXTENSIONS_SHELL_TEST_SHELL_TEST_H_
 
 #include <memory>
 
 #include "content/public/test/browser_test.h"
 #include "content/public/test/browser_test_base.h"
+#include "extensions/common/features/feature_channel.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 
 class ShellExtensionSystem;
 
 // Base class for app shell browser tests.
 class AppShellTest : public content::BrowserTestBase {
  public:
   AppShellTest();
   ~AppShellTest() override;
 
   // content::BrowserTestBase implementation.
   void SetUp() override;
   void SetUpOnMainThread() override;
   void RunTestOnMainThreadLoop() override;
 
   content::BrowserContext* browser_context() { return browser_context_; }
 
  protected:
   content::BrowserContext* browser_context_;
   ShellExtensionSystem* extension_system_;
+  ScopedCurrentChannel current_channel_;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_SHELL_TEST_SHELL_TEST_H_