Extract InstallVerifier from ExtensionSystem.

extensions/shell/browser/shell_extension_system.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_BROWSER_SHELL_EXTENSION_SYSTEM_H_
 #define EXTENSIONS_SHELL_BROWSER_SHELL_EXTENSION_SYSTEM_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 45 matching lines @@
   ExtensionService* extension_service() override;
   RuntimeData* runtime_data() override;
   ManagementPolicy* management_policy() override;
   SharedUserScriptMaster* shared_user_script_master() override;
   DeclarativeUserScriptManager* declarative_user_script_manager() override;
   StateStore* state_store() override;
   StateStore* rules_store() override;
   InfoMap* info_map() override;
   LazyBackgroundTaskQueue* lazy_background_task_queue() override;
   EventRouter* event_router() override;
-  InstallVerifier* install_verifier() override;
   QuotaService* quota_service() override;
   void RegisterExtensionWithRequestContexts(
       const Extension* extension) override;
   void UnregisterExtensionWithRequestContexts(
       const std::string& extension_id,
       const UnloadedExtensionInfo::Reason reason) override;
   const OneShotEvent& ready() const override;
   ContentVerifier* content_verifier() override;
   scoped_ptr<ExtensionSet> GetDependentExtensions(
       const Extension* extension) override;
@@ skipping 11 matching lines @@
 
   // Signaled when the extension system has completed its startup tasks.
   OneShotEvent ready_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellExtensionSystem);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_SHELL_BROWSER_SHELL_EXTENSION_SYSTEM_H_