Sync removal of Default apps.

chrome/browser/ui/app_list/app_list_syncable_service.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/ui/app_list/app_list_syncable_service.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/app_list/app_list_service.h"
 #include "chrome/browser/ui/app_list/extension_app_item.h"
 #include "chrome/browser/ui/app_list/extension_app_model_builder.h"
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/common/chrome_switches.h"
 #include "content/public/browser/notification_source.h"
 #include "sync/api/sync_change_processor.h"
 #include "sync/api/sync_data.h"
 #include "sync/api/sync_merge_result.h"
 #include "sync/protocol/sync.pb.h"
+#include "ui/app_list/app_list_folder_item.h"
 #include "ui/app_list/app_list_item.h"
 #include "ui/app_list/app_list_model.h"
 
 using syncer::SyncChange;
 
 namespace app_list {
 
 namespace {
 
 void UpdateSyncItemFromSync(const sync_pb::AppListSpecifics& specifics,
                             AppListSyncableService::SyncItem* item) {
   DCHECK_EQ(item->item_id, specifics.item_id());
   item->item_type = specifics.item_type();
   item->item_name = specifics.item_name();
   item->parent_id = specifics.parent_id();
   if (!specifics.page_ordinal().empty())
     item->page_ordinal = syncer::StringOrdinal(specifics.page_ordinal());
   if (!specifics.item_ordinal().empty())
     item->item_ordinal = syncer::StringOrdinal(specifics.item_ordinal());
 }
 
 bool UpdateSyncItemFromAppItem(const AppListItem* app_item,
                                AppListSyncableService::SyncItem* sync_item) {
   DCHECK_EQ(sync_item->item_id, app_item->id());
   bool changed = false;
+  if (sync_item->item_name != app_item->title()) {
+    sync_item->item_name = app_item->title();
+    changed = true;
+  }
   if (!sync_item->item_ordinal.IsValid() ||
       !app_item->position().Equals(sync_item->item_ordinal)) {
     sync_item->item_ordinal = app_item->position();
     changed = true;
   }
   // TODO(stevenjb): Set parent_id and page_ordinal.
   return changed;
 }
 
 void GetSyncSpecificsFromSyncItem(const AppListSyncableService::SyncItem* item,
@@ skipping 11 matching lines @@
 
 syncer::SyncData GetSyncDataFromSyncItem(
     const AppListSyncableService::SyncItem* item) {
   sync_pb::EntitySpecifics specifics;
   GetSyncSpecificsFromSyncItem(item, specifics.mutable_app_list());
   return syncer::SyncData::CreateLocalData(item->item_id,
                                            item->item_id,
                                            specifics);
 }
 
+bool AppIsDefault(ExtensionService* service, const std::string& id) {
+  return service && service->extension_prefs()->WasInstalledByDefault(id);
+}
+
+bool AppIsPlatformApp(ExtensionService* service, const std::string& id) {
+  if (!service)
+    return false;
+  const extensions::Extension* app = service->GetInstalledExtension(id);
+  DVLOG_IF(1, !app) << "No App for ID: " << id;
+  return app ? app->is_platform_app() : false;
+}
+
+void UninstallExtension(ExtensionService* service, const std::string& id) {
+  if (service && service->GetInstalledExtension(id))
+    service->UninstallExtension(id, false, NULL);
+}
+
 }  // namespace
 
 // AppListSyncableService::SyncItem
 
 AppListSyncableService::SyncItem::SyncItem(
     const std::string& id,
     sync_pb::AppListSpecifics::AppListItemType type)
     : item_id(id),
       item_type(type) {
 }
 
 AppListSyncableService::SyncItem::~SyncItem() {
 }
 
 // AppListSyncableService
 
 AppListSyncableService::AppListSyncableService(
     Profile* profile,
-    ExtensionService* extension_service)
+    extensions::ExtensionSystem* extension_system)
     : profile_(profile),
+      extension_system_(extension_system),
       model_(new AppListModel) {
-  if (extension_service && extension_service->is_ready()) {
+  if (!extension_system || !extension_system->extension_service()) {
+    LOG(WARNING) << "AppListSyncableService created with no ExtensionService";
+    return;
+  }
+
+  if (extension_system->extension_service()->is_ready()) {
     BuildModel();
     return;
   }
 
   // The extensions for this profile have not yet all been loaded.
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSIONS_READY,
                  content::Source<Profile>(profile));
 }
 
 AppListSyncableService::~AppListSyncableService() {
@@ skipping 35 matching lines @@
 }
 
 const AppListSyncableService::SyncItem*
 AppListSyncableService::GetSyncItem(const std::string& id) const {
   SyncItemMap::const_iterator iter = sync_items_.find(id);
   if (iter != sync_items_.end())
     return iter->second;
   return NULL;
 }
 
-void AppListSyncableService::AddExtensionAppItem(ExtensionAppItem* item) {
-  SyncItem* sync_item = AddItem(
-      sync_pb::AppListSpecifics_AppListItemType_TYPE_APP, item);
-  if (!sync_item)
-    return;  // Item already exists.
-  sync_item->item_name = item->extension_name();
+void AppListSyncableService::AddItem(AppListItem* item) {
+  const std::string& item_id = item->id();
+  if (item_id.empty()) {
+    LOG(ERROR) << "AppListItem item with empty ID";
+    return;
+  }
+  sync_pb::AppListSpecifics::AppListItemType type;
+  const char* item_type = item->GetAppType();
+  if (item_type == ExtensionAppItem::kAppType) {
+    type = sync_pb::AppListSpecifics_AppListItemType_TYPE_APP;
+  } else if (item_type == AppListFolderItem::kAppType) {
+    type = sync_pb::AppListSpecifics_AppListItemType_TYPE_FOLDER;
+  } else {
+    LOG(ERROR) << "Unrecognized model type: " << item_type;
+    return;
+  }
+  SyncItem* sync_item = FindSyncItem(item_id);
+  if (sync_item) {
+    // If there is an existing, non-REMOVE_DEFAULT entry, update it.
+    if (sync_item->item_type !=
+        sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP) {
+      DCHECK_EQ(sync_item->item_type, type);
+      DVLOG(2) << this << ": AddItem already exists: " << sync_item->ToString();
+      UpdateItem(item);
+      return;
+    }
+    // If there is an existing REMOVE_DEFAULT_APP entry, and the app is
+    // installed as a Default app, uninstall the app instead of adding it.
+    if (type == sync_pb::AppListSpecifics_AppListItemType_TYPE_APP &&
+        AppIsDefault(extension_system_->extension_service(), item_id)) {
+      DVLOG(1) << this << ": AddItem: Uninstall: " << sync_item->ToString();
+      UninstallExtension(extension_system_->extension_service(), item_id);

[Nicolas Zea, 2013/12/30 19:49:00]

Has the App already been installed at this point? It seems odd to go about the
install process unnecessarily if we can detect ahead of time that we're going to
have to uninstall it.

[stevenjb, 2014/01/02 21:15:49]

Default apps are installed once on creation of a new Profile. This code is
currently independent of the AppList and of App sync in general. While we could
provide a mechanism to query whether or not an existing REMOVE_DEFAULT entry
exists, it is unlikely that sync will have completed at the time default apps
are installed. We would need to delay the installation of default apps until app
+ app list sync has completed. While I agree that would be nice, it seems like
unnecessary complexity for a relatively minor optimization.

+      return;
+    }
+    // Otherwise, we are adding the app as a non-default app (i.e. an app that
+    // was installed by Default and removed is getting installed explicitly by
+    // the user), so delete the REMOVE_DEFAULT_APP.
+    if (SyncStarted()) {
+      DVLOG(2) << this << " -> SYNC DELETE: " << sync_item->ToString();
+      SyncChange sync_change(FROM_HERE, SyncChange::ACTION_DELETE,
+                             GetSyncDataFromSyncItem(sync_item));
+      sync_processor_->ProcessSyncChanges(
+          FROM_HERE, syncer::SyncChangeList(1, sync_change));
+    }
+    delete sync_item;
+    sync_items_.erase(item_id);
+    // Fall through. The REMOVE_DEFAULT_APP entry has been deleted, now an App
+    // entry can be added as usual.
+  }
+
+  sync_item = CreateSyncItem(item_id, type);
+  UpdateSyncItemFromAppItem(item, sync_item);
+  model_->item_list()->AddItem(item);
+  DVLOG(1) << this << ": AddItem: " << sync_item->ToString() << " Default: "
+           << AppIsDefault(extension_system_->extension_service(), item->id());
   SendSyncChange(sync_item, SyncChange::ACTION_ADD);
 }
 
-void AppListSyncableService::UpdateExtensionAppItem(ExtensionAppItem* item) {
+void AppListSyncableService::UpdateItem(AppListItem* item) {
   SyncItem* sync_item = FindSyncItem(item->id());
   if (!sync_item) {
-    LOG(ERROR) << "UpdateExtensionAppItem: no sync item: " << item->id();
+    LOG(ERROR) << "UpdateItem: no sync item: " << item->id();
     return;
   }
   bool changed = UpdateSyncItemFromAppItem(item, sync_item);
-  if (sync_item->item_name != item->extension_name()) {
-    sync_item->item_name = item->extension_name();
-    changed = true;
-  }
   if (!changed) {
     DVLOG(2) << this << " - Update: SYNC NO CHANGE: " << sync_item->ToString();
     return;
   }
   SendSyncChange(sync_item, SyncChange::ACTION_UPDATE);
 }
 
 void AppListSyncableService::RemoveItem(const std::string& id) {
   DVLOG(2) << this << ": RemoveItem: " << id.substr(0, 8);
   SyncItemMap::iterator iter = sync_items_.find(id);
-  if (iter == sync_items_.end())
+  if (iter == sync_items_.end()) {
+    DVLOG(2) << this << " : No Sync Item.";
     return;
+  }
+  // Always delete the item from the model.
+  model_->item_list()->DeleteItem(id);
+
+  // Check for existing RemoveDefault sync item.
   SyncItem* sync_item = iter->second;
+  if (sync_item->item_type ==
+      sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP) {
+    // RemoveDefault item exists, just return.
+    DVLOG(2) << this << " : RemoveDefault Item exists.";
+    return;
+  }
+
+  // Existing entry is a normal entry, send a Delete sync change and remove
+  // the entry.
   if (SyncStarted()) {
     DVLOG(2) << this << " -> SYNC DELETE: " << sync_item->ToString();
     SyncChange sync_change(FROM_HERE, SyncChange::ACTION_DELETE,
                            GetSyncDataFromSyncItem(sync_item));
     sync_processor_->ProcessSyncChanges(
         FROM_HERE, syncer::SyncChangeList(1, sync_change));
   }
   delete sync_item;
   sync_items_.erase(iter);
-  model_->item_list()->DeleteItem(id);
+
+  if (!AppIsDefault(extension_system_->extension_service(), id))
+    return;
+  // This is a Default app; create and send a REMOVE_DEFAULT sync change.
+  // Note: we add the REMOVE_DEFAULT entry after we delete the existing entry.
+  sync_item = CreateSyncItem(
+      id, sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP);
+  DVLOG(1) << this << ": RemoveDefaultItem: " << sync_item->ToString();
+  SendSyncChange(sync_item, SyncChange::ACTION_ADD);
 }
 
 // AppListSyncableService syncer::SyncableService
 
 syncer::SyncMergeResult AppListSyncableService::MergeDataAndStartSyncing(
     syncer::ModelType type,
     const syncer::SyncDataList& initial_sync_data,
     scoped_ptr<syncer::SyncChangeProcessor> sync_processor,
     scoped_ptr<syncer::SyncErrorFactory> error_handler) {
   DCHECK(!sync_processor_.get());
@@ skipping 13 matching lines @@
   for (SyncItemMap::const_iterator iter = sync_items_.begin();
        iter != sync_items_.end(); ++iter) {
     unsynced_items.insert(iter->first);
   }
 
   // Create SyncItem entries for initial_sync_data.
   size_t new_items = 0, updated_items = 0;
   for (syncer::SyncDataList::const_iterator iter = initial_sync_data.begin();
        iter != initial_sync_data.end(); ++iter) {
     const syncer::SyncData& data = *iter;
+    DVLOG(2) << this << "  Initial Sync Item: "
+             << data.GetSpecifics().app_list().item_id()
+             << " Type: " << data.GetSpecifics().app_list().item_type();
     DCHECK_EQ(syncer::APP_LIST, data.GetDataType());
-    if (CreateOrUpdateSyncItem(data.GetSpecifics().app_list()))
+    if (ProcessSyncItem(data.GetSpecifics().app_list()))
       ++new_items;
     else
       ++updated_items;
     unsynced_items.erase(data.GetSpecifics().app_list().item_id());
   }
 
   result.set_num_items_after_association(sync_items_.size());
   result.set_num_items_added(new_items);
   result.set_num_items_deleted(0);
   result.set_num_items_modified(updated_items);
@@ skipping 16 matching lines @@
   DCHECK_EQ(type, syncer::APP_LIST);
 
   sync_processor_.reset();
   sync_error_handler_.reset();
 }
 
 syncer::SyncDataList AppListSyncableService::GetAllSyncData(
     syncer::ModelType type) const {
   DCHECK_EQ(syncer::APP_LIST, type);
 
-  DVLOG(1) << this << "GetAllSyncData: " << sync_items_.size();
+  DVLOG(1) << this << ": GetAllSyncData: " << sync_items_.size();
   syncer::SyncDataList list;
   for (SyncItemMap::const_iterator iter = sync_items_.begin();
        iter != sync_items_.end(); ++iter) {
     DVLOG(2) << this << " -> SYNC: " << iter->second->ToString();
     list.push_back(GetSyncDataFromSyncItem(iter->second));
   }
   return list;
 }
 
 syncer::SyncError AppListSyncableService::ProcessSyncChanges(
     const tracked_objects::Location& from_here,
     const syncer::SyncChangeList& change_list) {
   if (!sync_processor_.get()) {
     return syncer::SyncError(FROM_HERE,
                              syncer::SyncError::DATATYPE_ERROR,
                              "App List syncable service is not started.",
                              syncer::APP_LIST);
   }
 
-  // Process incoming changes first.
   DVLOG(1) << this << ": ProcessSyncChanges: " << change_list.size();
   for (syncer::SyncChangeList::const_iterator iter = change_list.begin();
        iter != change_list.end(); ++iter) {
     const SyncChange& change = *iter;
+    DVLOG(2) << this << "  Change: "
+             << change.sync_data().GetSpecifics().app_list().item_id()
+             << " (" << change.change_type() << ")";
     if (change.change_type() == SyncChange::ACTION_ADD ||
         change.change_type() == SyncChange::ACTION_UPDATE) {
-      CreateOrUpdateSyncItem(change.sync_data().GetSpecifics().app_list());
+      ProcessSyncItem(change.sync_data().GetSpecifics().app_list());
     } else if (change.change_type() == SyncChange::ACTION_DELETE) {
       DeleteSyncItem(change.sync_data().GetSpecifics().app_list());
     } else {
       LOG(ERROR) << "Invalid sync change";
     }
   }
   return syncer::SyncError();
 }
 
 // AppListSyncableService private
 
-void AppListSyncableService::CreateAppItemFromSyncItem(SyncItem* sync_item) {
-  if (sync_item->item_type == sync_pb::AppListSpecifics::TYPE_APP) {
-    std::string extension_id = sync_item->item_id;
-    const ExtensionService* extension_service =
-        extensions::ExtensionSystem::Get(profile_)->extension_service();
-    const extensions::Extension* app =
-        extension_service->GetInstalledExtension(extension_id);
-    DVLOG_IF(1, !app) << this << "No App for ID: " << extension_id;
-    bool is_platform_app = app ? app->is_platform_app() : false;
-    ExtensionAppItem* app_item = new ExtensionAppItem(
-        profile_,
-        sync_item,
-        extension_id,
-        sync_item->item_name,
-        gfx::ImageSkia(),
-        is_platform_app);
-    model_->item_list()->AddItem(app_item);
-    return;
+bool AppListSyncableService::ProcessSyncItem(
+    const sync_pb::AppListSpecifics& specifics) {
+  const std::string& item_id = specifics.item_id();
+  if (item_id.empty()) {
+    LOG(ERROR) << "AppList item with empty ID";
+    return false;
   }
-  if (sync_item->item_type ==
+  SyncItem* sync_item = FindSyncItem(item_id);
+  if (sync_item) {
+    // If an item of the same type exists, update it.
+    if (sync_item->item_type == specifics.item_type()) {
+      UpdateSyncItemFromSync(specifics, sync_item);
+      ProcessExistingSyncItem(sync_item);
+      DVLOG(2) << this << " <- SYNC UPDATE: " << sync_item->ToString();
+      return false;
+    }
+    // Otherwise, one of the entries should be TYPE_REMOVE_DEFAULT_APP.
+    if (sync_item->item_type !=
+        sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP &&
+        specifics.item_type() !=
+        sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP) {
+      LOG(ERROR) << "Synced item type: " << specifics.item_type()
+                 << " != existing sync item type: " << sync_item->item_type
+                 << " Deleting item from model!";
+      model_->item_list()->DeleteItem(item_id);
+    }
+    DVLOG(2) << this << " - ProcessSyncItem: Delete existing entry: "
+             << sync_item->ToString();
+    delete sync_item;
+    sync_items_.erase(item_id);
+  }
+
+  sync_item = CreateSyncItem(item_id, specifics.item_type());
+  UpdateSyncItemFromSync(specifics, sync_item);
+  ProcessNewSyncItem(sync_item);
+  DVLOG(2) << this << " <- SYNC ADD: " << sync_item->ToString();
+  return true;
+}
+
+void AppListSyncableService::ProcessNewSyncItem(SyncItem* sync_item) {
+  switch (sync_item->item_type) {
+    case sync_pb::AppListSpecifics::TYPE_APP: {
+      std::string extension_id = sync_item->item_id;
+      bool is_platform_app =
+          AppIsPlatformApp(extension_system_->extension_service(),
+                           extension_id);
+      ExtensionAppItem* app_item = new ExtensionAppItem(
+          profile_,
+          sync_item,
+          extension_id,
+          sync_item->item_name,
+          gfx::ImageSkia(),
+          is_platform_app);
+      model_->item_list()->AddItem(app_item);
+      return;
+    }
+    case sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP: {
+      DVLOG(1) << this << ": Uninstall: " << sync_item->ToString();
+      UninstallExtension(extension_system_->extension_service(),
+                         sync_item->item_id);
+      return;
+    }
+    case sync_pb::AppListSpecifics::TYPE_FOLDER: {
+      // TODO(stevenjb): Implement
+      LOG(WARNING) << "TYPE_FOLDER not supported";
+      return;
+    }
+    case sync_pb::AppListSpecifics::TYPE_URL: {
+      // TODO(stevenjb): Implement
+      LOG(WARNING) << "TYPE_URL not supported";
+      return;
+    }
+  }
+  NOTREACHED() << "Unrecoginized sync item type: " << sync_item->ToString();
+}
+
+void AppListSyncableService::ProcessExistingSyncItem(SyncItem* sync_item) {
+  if (sync_item->item_type !=
       sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP) {
-    // TODO(stevenjb): Implement
+    AppListItem* item = model_->item_list()->FindItem(sync_item->item_id);
+    if (item && !item->position().Equals(sync_item->item_ordinal))
+      model_->item_list()->SetItemPosition(item, sync_item->item_ordinal);
   }
-  if (sync_item->item_type == sync_pb::AppListSpecifics::TYPE_FOLDER) {
-    // TODO(stevenjb): Implement
-  }
-  if (sync_item->item_type == sync_pb::AppListSpecifics::TYPE_URL) {
-    // TODO(stevenjb): Implement
-  }
-  LOG(ERROR) << "Unsupported type: " << sync_item->item_type;
 }
 
 bool AppListSyncableService::SyncStarted() {
   if (sync_processor_.get())
     return true;
   if (flare_.is_null()) {
     DVLOG(2) << this << ": SyncStarted: Flare.";
     flare_ = sync_start_util::GetFlareForSyncableService(profile_->GetPath());
     flare_.Run(syncer::APP_LIST);
   }
   return false;
 }
 
-AppListSyncableService::SyncItem* AppListSyncableService::AddItem(
-    sync_pb::AppListSpecifics::AppListItemType type,
-    AppListItem* app_item) {
-  const std::string& item_id = app_item->id();
-  if (item_id.empty()) {
-    LOG(ERROR) << "AppListItem item with empty ID";
-    return NULL;
-  }
-  bool new_item = false;
-  SyncItem* sync_item = FindOrCreateSyncItem(item_id, type, &new_item);
-  if (!new_item) {
-    DVLOG(2) << this << ": AddItem already exists: " << sync_item->ToString();
-    return NULL;  // Item already exists.
-  }
-  UpdateSyncItemFromAppItem(app_item, sync_item);
-  DVLOG(1) << this << ": AddItem: " << sync_item->ToString();
-  model_->item_list()->AddItem(app_item);
-  return sync_item;
-}
-
 void AppListSyncableService::SendSyncChange(
     SyncItem* sync_item,
     SyncChange::SyncChangeType sync_change_type) {
   if (!SyncStarted()) {
     DVLOG(2) << this << " - SendSyncChange: SYNC NOT STARTED: "
              << sync_item->ToString();
     return;
   }
   if (sync_change_type == SyncChange::ACTION_ADD)
     DVLOG(2) << this << " -> SYNC ADD: " << sync_item->ToString();
   else
     DVLOG(2) << this << " -> SYNC UPDATE: " << sync_item->ToString();
   SyncChange sync_change(FROM_HERE, sync_change_type,
                          GetSyncDataFromSyncItem(sync_item));
   sync_processor_->ProcessSyncChanges(
       FROM_HERE, syncer::SyncChangeList(1, sync_change));
 }
 
 AppListSyncableService::SyncItem*
 AppListSyncableService::FindSyncItem(const std::string& item_id) {
   SyncItemMap::iterator iter = sync_items_.find(item_id);
   if (iter == sync_items_.end())
     return NULL;
   return iter->second;
 }
 
-AppListSyncableService::SyncItem* AppListSyncableService::FindOrCreateSyncItem(
+AppListSyncableService::SyncItem*
+AppListSyncableService::CreateSyncItem(
     const std::string& item_id,
-    sync_pb::AppListSpecifics::AppListItemType type,
-    bool* new_item) {
-  SyncItem* item = FindSyncItem(item_id);
-  if (item) {
-    DCHECK(type == item->item_type);
-    *new_item = false;
-    return item;
-  }
-
-  item = new SyncItem(item_id, type);
-  sync_items_[item_id] = item;
-  *new_item = true;
-  return item;
-}
-
-bool AppListSyncableService::CreateOrUpdateSyncItem(
-    const sync_pb::AppListSpecifics& specifics) {
-  const std::string& item_id = specifics.item_id();
-  if (item_id.empty()) {
-    LOG(ERROR) << "CreateOrUpdate AppList item with empty ID";
-    return false;
-  }
-  bool new_item = false;
-  SyncItem* sync_item =
-      FindOrCreateSyncItem(item_id, specifics.item_type(), &new_item);
-  DVLOG(2) << this << "CreateOrUpdateSyncItem: " << sync_item->ToString()
-           << " New: " << new_item << " Pos: " << specifics.item_ordinal();
-  UpdateSyncItemFromSync(specifics, sync_item);
-  // Update existing item in model
-  AppListItem* item = model_->item_list()->FindItem(sync_item->item_id);
-  if (item && !item->position().Equals(sync_item->item_ordinal))
-    model_->item_list()->SetItemPosition(item, sync_item->item_ordinal);
-  if (new_item) {
-    CreateAppItemFromSyncItem(sync_item);
-    DVLOG(2) << this << " <- SYNC ADD: " << sync_item->ToString();
-  } else {
-    DVLOG(2) << this << " <- SYNC UPDATE: " << sync_item->ToString();
-  }
-  return new_item;
+    sync_pb::AppListSpecifics::AppListItemType item_type) {
+  DCHECK(!ContainsKey(sync_items_, item_id));
+  SyncItem* sync_item = new SyncItem(item_id, item_type);
+  sync_items_[item_id] = sync_item;
+  return sync_item;
 }
 
 void AppListSyncableService::DeleteSyncItem(
     const sync_pb::AppListSpecifics& specifics) {
   const std::string& item_id = specifics.item_id();
   if (item_id.empty()) {
     LOG(ERROR) << "Delete AppList item with empty ID";
     return;
   }
-  DVLOG(2) << this << "DeleteSyncItem: " << item_id.substr(0, 8);
+  DVLOG(2) << this << ": DeleteSyncItem: " << item_id.substr(0, 8);
   SyncItemMap::iterator iter = sync_items_.find(item_id);
   if (iter == sync_items_.end())
     return;
+  sync_pb::AppListSpecifics::AppListItemType item_type =
+      iter->second->item_type;
   DVLOG(2) << this << " <- SYNC DELETE: " << iter->second->ToString();
   delete iter->second;
   sync_items_.erase(iter);
-  model_->item_list()->DeleteItem(item_id);
+  if (item_type != sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP)
+    model_->item_list()->DeleteItem(item_id);
 }
 
 std::string AppListSyncableService::SyncItem::ToString() const {
-  return item_id.substr(0, 8) + " [" + item_ordinal.ToDebugString() + "]";
+  std::string res = item_id.substr(0, 8);
+  if (item_type == sync_pb::AppListSpecifics::TYPE_REMOVE_DEFAULT_APP) {
+    res += " { RemoveDefault }";
+  } else {
+    res += " { " + item_name + " }";
+    res += " [" + item_ordinal.ToDebugString() + "]";
+  }
+  return res;
 }
 
 }  // namespace app_list