Revert "Move ExtensionCache to //extensions"

extensions/shell/browser/shell_extensions_browser_client.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_EXTENSIONS_BROWSER_CLIENT_H_
 #define EXTENSIONS_SHELL_BROWSER_SHELL_EXTENSIONS_BROWSER_CLIENT_H_
 
 #include "base/compiler_specific.h"
 #include "extensions/browser/extensions_browser_client.h"
 
@@ skipping 60 matching lines @@
   virtual void RegisterExtensionFunctions(
       ExtensionFunctionRegistry* registry) const override;
   virtual scoped_ptr<RuntimeAPIDelegate> CreateRuntimeAPIDelegate(
       content::BrowserContext* context) const override;
   virtual ComponentExtensionResourceManager*
       GetComponentExtensionResourceManager() override;
   virtual void BroadcastEventToRenderers(
       const std::string& event_name,
       scoped_ptr<base::ListValue> args) override;
   virtual net::NetLog* GetNetLog() override;
-  virtual ExtensionCache* GetExtensionCache() override;
 
  private:
   // The single BrowserContext for app_shell. Not owned.
   content::BrowserContext* browser_context_;
 
   // Support for extension APIs.
   scoped_ptr<ExtensionsAPIClient> api_client_;
 
   // The PrefService for |browser_context_|.
   scoped_ptr<PrefService> prefs_;
 
-  // The extension cache used for download and installation.
-  scoped_ptr<ExtensionCache> extension_cache_;
-
   DISALLOW_COPY_AND_ASSIGN(ShellExtensionsBrowserClient);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_SHELL_BROWSER_SHELL_EXTENSIONS_BROWSER_CLIENT_H_