Add extensions code to use common updater in components/update_client/

chrome/browser/extensions/extension_system_impl.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 CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_IMPL_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_IMPL_H_
 
 #include "extensions/browser/extension_system.h"
 #include "extensions/common/one_shot_event.h"
 
@@ skipping 36 matching lines @@
       const base::Closure& callback) override;
 
   void UnregisterExtensionWithRequestContexts(
       const std::string& extension_id,
       const UnloadedExtensionInfo::Reason reason) override;
 
   const OneShotEvent& ready() const override;
   ContentVerifier* content_verifier() override;  // shared
   scoped_ptr<ExtensionSet> GetDependentExtensions(
       const Extension* extension) override;
+  void InstallUpdate(const std::string& extension_id,
+                     const base::FilePath& temp_dir) override;
 
  private:
   friend class ExtensionSystemSharedFactory;
 
   // Owns the Extension-related systems that have a single instance
   // shared between normal and incognito profiles.
   class Shared : public KeyedService {
    public:
     explicit Shared(Profile* profile);
     ~Shared() override;
@@ skipping 57 matching lines @@
   Profile* profile_;
 
   Shared* shared_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionSystemImpl);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SYSTEM_IMPL_H_