Use PreloadCheckGroup in ExtensionInstallChecker. Make RequirementsChecker a PreloadCheck.

extensions/browser/api/management/management_api_delegate.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_API_MANAGEMENT_MANAGEMENT_API_DELEGATE_H_
 #define EXTENSIONS_BROWSER_API_MANAGEMENT_MANAGEMENT_API_DELEGATE_H_
 
 #include "base/callback.h"
 #include "extensions/browser/uninstall_reason.h"
 #include "extensions/common/constants.h"
@@ skipping 65 matching lines @@
       const std::string& manifest_str) const = 0;
 
   // Used to show a dialog prompt in chrome when management.setEnabled extension
   // function is called.
   virtual std::unique_ptr<InstallPromptDelegate> SetEnabledFunctionDelegate(
       content::WebContents* web_contents,
       content::BrowserContext* browser_context,
       const Extension* extension,
       const base::Callback<void(bool)>& callback) const = 0;
 
-  // Returns a new RequirementsChecker.
-  virtual std::unique_ptr<RequirementsChecker> CreateRequirementsChecker()
-      const = 0;
-
   // Enables the extension identified by |extension_id|.
   virtual void EnableExtension(content::BrowserContext* context,
                                const std::string& extension_id) const = 0;
 
   // Disables the extension identified by |extension_id|.
   virtual void DisableExtension(
       content::BrowserContext* context,
       const std::string& extension_id,
       Extension::DisableReason disable_reason) const = 0;
 
@@ skipping 32 matching lines @@
   // Forwards the call to ExtensionIconSource::GetIconURL in chrome.
   virtual GURL GetIconURL(const Extension* extension,
                           int icon_size,
                           ExtensionIconSet::MatchType match,
                           bool grayscale) const = 0;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_MANAGEMENT_MANAGEMENT_API_DELEGATE_H_