Add skeleton for select-to-speak component extension.

chrome/browser/chromeos/accessibility/accessibility_manager.h

 // Copyright (c) 2013 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 CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
 
 #include <set>
 
 #include "ash/common/accessibility_types.h"
@@ skipping 388 matching lines @@
   // Listen to extension unloaded notifications.
   ScopedObserver<extensions::ExtensionRegistry,
                  extensions::ExtensionRegistryObserver>
       extension_registry_observer_;
 
   std::unique_ptr<AccessibilityHighlightManager>
       accessibility_highlight_manager_;
 
   std::unique_ptr<AccessibilityExtensionLoader> chromevox_loader_;
 
+  std::unique_ptr<AccessibilityExtensionLoader> select_to_speak_loader_;
+
   base::WeakPtrFactory<AccessibilityManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_