Extension syncing: Introduce a NeedsSync pref

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 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_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 
@@ skipping 849 matching lines @@
 
   NotifyExtensionLoaded(extension);
 
   // Notify listeners that the extension was enabled.
   content::NotificationService::current()->Notify(
       extensions::NOTIFICATION_EXTENSION_ENABLED,
       content::Source<Profile>(profile_),
       content::Details<const Extension>(extension));
 
   if (extension_sync_service_)
-    extension_sync_service_->SyncEnableExtension(*extension);
+    extension_sync_service_->SyncExtensionChangeIfNeeded(*extension);
 }
 
 void ExtensionService::DisableExtension(const std::string& extension_id,
                                         int disable_reasons) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   // The extension may have been disabled already. Just add a disable reason.
   if (!IsExtensionEnabled(extension_id)) {
     extension_prefs_->AddDisableReasons(extension_id, disable_reasons);
     return;
@@ skipping 30 matching lines @@
   // for terminated extensions being disabled.
   registry_->AddDisabled(make_scoped_refptr(extension));
   if (registry_->enabled_extensions().Contains(extension->id())) {
     registry_->RemoveEnabled(extension->id());
     NotifyExtensionUnloaded(extension, UnloadedExtensionInfo::REASON_DISABLE);
   } else {
     registry_->RemoveTerminated(extension->id());
   }
 
   if (extension_sync_service_)
-    extension_sync_service_->SyncDisableExtension(*extension);
+    extension_sync_service_->SyncExtensionChangeIfNeeded(*extension);
 }
 
 void ExtensionService::DisableUserExtensions(
     const std::vector<std::string>& except_ids) {
   extensions::ManagementPolicy* management_policy =
       system_->management_policy();
   extensions::ExtensionList to_disable;
 
   const ExtensionSet& enabled_set = registry_->enabled_extensions();
   for (ExtensionSet::const_iterator extension = enabled_set.begin();
@@ skipping 1646 matching lines @@
 }
 
 void ExtensionService::OnProfileDestructionStarted() {
   ExtensionIdSet ids_to_unload = registry_->enabled_extensions().GetIDs();
   for (ExtensionIdSet::iterator it = ids_to_unload.begin();
        it != ids_to_unload.end();
        ++it) {
     UnloadExtension(*it, UnloadedExtensionInfo::REASON_PROFILE_SHUTDOWN);
   }
 }