Add a do_not_sync pref to ExtensionPrefs.

chrome/browser/extensions/extension_util.cc

 // Copyright 2013 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_util.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ skipping 162 matching lines @@
   return !(ExtensionPrefs::Get(context)->GetDisableReasons(extension_id) &
            Extension::DISABLE_UNSUPPORTED_REQUIREMENT);
 }
 
 bool IsAppLaunchableWithoutEnabling(const std::string& extension_id,
                                     content::BrowserContext* context) {
   return ExtensionRegistry::Get(context)->GetExtensionById(
       extension_id, ExtensionRegistry::ENABLED) != NULL;
 }
 
+bool ShouldSyncExtension(const Extension* extension,
+                         content::BrowserContext* context) {
+  return sync_helper::IsSyncableExtension(extension) &&
+         !ExtensionPrefs::Get(context)->DoNotSync(extension->id());
+}
+
 bool ShouldSyncApp(const Extension* app, content::BrowserContext* context) {
   return sync_helper::IsSyncableApp(app) &&
-      !util::IsEphemeralApp(app->id(), context);
+         !util::IsEphemeralApp(app->id(), context) &&
+         !ExtensionPrefs::Get(context)->DoNotSync(app->id());
 }
 
 bool IsExtensionIdle(const std::string& extension_id,
                      content::BrowserContext* context) {
   ProcessManager* process_manager =
       ExtensionSystem::Get(context)->process_manager();
   DCHECK(process_manager);
   ExtensionHost* host =
       process_manager->GetBackgroundHostForExtension(extension_id);
   if (host)
@@ skipping 76 matching lines @@
       IDR_APP_DEFAULT_ICON);
 }
 
 const gfx::ImageSkia& GetDefaultExtensionIcon() {
   return *ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
       IDR_EXTENSION_DEFAULT_ICON);
 }
 
 }  // namespace util
 }  // namespace extensions