Disable sync for default apps

chrome/browser/extensions/extension_service.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.
 
 #include "chrome/browser/extensions/extension_service.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 607 matching lines @@
     creation_flags |= Extension::FROM_WEBSTORE;
   }
 
   // Bookmark apps being updated is kind of a contradiction, but that's because
   // we mark the default apps as bookmark apps, and they're hosted in the web
   // store, thus they can get updated. See http://crbug.com/101605 for more
   // details.
   if (extension && extension->from_bookmark())
     creation_flags |= Extension::FROM_BOOKMARK;
 
+  if (extension && extension->was_installed_by_default())
+    creation_flags |= Extension::WAS_INSTALLED_BY_DEFAULT;
+
   installer->set_creation_flags(creation_flags);
 
   installer->set_delete_source(true);
   installer->set_download_url(download_url);
   installer->set_install_cause(extension_misc::INSTALL_CAUSE_UPDATE);
   installer->InstallCrx(extension_path);
 
   if (out_crx_installer)
     *out_crx_installer = installer;
 
@@ skipping 1931 matching lines @@
 
 ExtensionService::NaClModuleInfoList::iterator
     ExtensionService::FindNaClModule(const GURL& url) {
   for (NaClModuleInfoList::iterator iter = nacl_module_list_.begin();
        iter != nacl_module_list_.end(); ++iter) {
     if (iter->url == url)
       return iter;
   }
   return nacl_module_list_.end();
 }