Ensure the ExtensionSystem is ready before initializing an ExtensionAppModelBuilder

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 "chrome/browser/chrome_notification_types.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_model_builder.h"
 #include "chrome/browser/ui/host_desktop.h"
+#include "content/public/browser/notification_source.h"
 #include "ui/app_list/app_list_model.h"
 
 namespace app_list {
 
 AppListSyncableService::AppListSyncableService(Profile* profile)
     : profile_(profile),
       model_(new AppListModel) {
+  ExtensionService* extension_service =
+      extensions::ExtensionSystem::Get(profile)->extension_service();

[benwells, 2013/11/21 00:47:47]

I prefer to pass this into the constructor, and have the factory obtain it. This
makes it clearer in the factory why the dependson is there, and means you can do
fun stuff in tests like pass in a test service.

[tapted, 2013/11/21 03:29:56]

Done modulo ExtensionSystem/ExtensionsService. (aside: anyone else thinking
those names are backward? Maybe we should rename ExtensionService ->
`ProfileExtensionSet` or `ExtensionSetManager`)

+  if (extension_service && 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() {
+}
+
+void AppListSyncableService::BuildModel() {
   // For now, use the AppListControllerDelegate associated with the native
   // desktop. TODO(stevenjb): Remove ExtensionAppModelBuilder controller
   // dependency and move the dependent methods from AppListControllerDelegate
   // to an extension service delegate associated with this class.
   AppListControllerDelegate* controller = NULL;
   AppListService* service =
       AppListService::Get(chrome::HOST_DESKTOP_TYPE_NATIVE);
   if (service)
     controller = service->GetControllerDelegate();
   apps_builder_.reset(
       new ExtensionAppModelBuilder(profile_, model_.get(), controller));
   DCHECK(profile_);
   VLOG(1) << "AppListSyncableService Created.";
 }
 
-AppListSyncableService::~AppListSyncableService() {
+void AppListSyncableService::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  DCHECK_EQ(chrome::NOTIFICATION_EXTENSIONS_READY, type);
+  DCHECK_EQ(profile_, content::Source<Profile>(source).ptr());
+  registrar_.RemoveAll();
+  BuildModel();
 }
 
 }  // namespace app_list