extensions: Cleanup class/struct fwd declarations

extensions/browser/extensions_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_BROWSER_EXTENSIONS_TEST_H_
 #define EXTENSIONS_BROWSER_EXTENSIONS_TEST_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "content/public/test/test_content_client_initializer.h"
 #include "content/public/test/test_renderer_host.h"
 #include "extensions/browser/mock_extension_system.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace content {
 class BrowserContext;
-class ContentBrowserClient;
-class ContentClient;
 class ContentUtilityClient;
 class RenderViewHostTestEnabler;
 }
 
 namespace extensions {
 class TestExtensionsBrowserClient;
 
 // Base class for extensions module unit tests of browser process code. Sets up
 // the content module and extensions module client interfaces. Initializes
 // services for a browser context.
@@ skipping 32 matching lines @@
   content::RenderViewHostTestEnabler rvh_test_enabler_;
 
   MockExtensionSystemFactory<MockExtensionSystem> extension_system_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionsTest);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EXTENSIONS_TEST_H_