Split ExtensionSystem interface from ExtensionSystemImpl implementation, part 1.

chrome/browser/download/download_crx_util.cc

 // Copyright (c) 2012 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.
 //
 // Download code which handles CRX files (extensions, themes, apps, ...).
 
 #include "chrome/browser/download/download_crx_util.h"
 
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/crx_installer.h"
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/webstore_installer.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/notification_service.h"
+#include "extensions/browser/extension_system.h"
 #include "extensions/common/user_script.h"
 
 using content::BrowserThread;
 using content::DownloadItem;
 using extensions::WebstoreInstaller;
 
 namespace download_crx_util {
 
 namespace {
 
@@ skipping 113 matching lines @@
   // The referrer URL must also be whitelisted, unless the URL has the file
   // scheme (there's no referrer for those URLs).
   // TODO(aa): RefererURL is cleared in some cases, for example when going
   // between secure and non-secure URLs. It would be better if DownloadItem
   // tracked the initiating page explicitly.
   return url_patterns.MatchesURL(item.GetReferrerUrl()) ||
          item.GetURL().SchemeIsFile();
 }
 
 }  // namespace download_crx_util