arc:Integration test for Arc package Chrome sync.

chrome/browser/ui/app_list/arc/arc_app_list_prefs_factory.cc

Index: chrome/browser/ui/app_list/arc/arc_app_list_prefs_factory.cc
diff --git a/chrome/browser/ui/app_list/arc/arc_app_list_prefs_factory.cc b/chrome/browser/ui/app_list/arc/arc_app_list_prefs_factory.cc
index 6ac101e160efa0f98dbb1631ae1810da9d33109a..fecaf94a69081c5224dfa18fb9ed1528f823f1b5 100644
--- a/chrome/browser/ui/app_list/arc/arc_app_list_prefs_factory.cc
+++ b/chrome/browser/ui/app_list/arc/arc_app_list_prefs_factory.cc
@@ -11,6 +11,8 @@
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "content/public/browser/browser_context.h"
 
+bool ArcAppListPrefsFactory::is_sync_test_ = false;
+
 // static
 ArcAppListPrefs* ArcAppListPrefsFactory::GetForBrowserContext(
     content::BrowserContext* context) {
@@ -23,6 +25,11 @@ ArcAppListPrefsFactory* ArcAppListPrefsFactory::GetInstance() {
   return base::Singleton<ArcAppListPrefsFactory>::get();
 }
 
+// static
+void ArcAppListPrefsFactory::SetFactoryForSyncTest() {
+  is_sync_test_ = true;
+}
+
 ArcAppListPrefsFactory::ArcAppListPrefsFactory()
     : BrowserContextKeyedServiceFactory(
           "ArcAppListPrefs",
@@ -38,6 +45,13 @@ KeyedService* ArcAppListPrefsFactory::BuildServiceInstanceFor(
   if (!arc::ArcAuthService::IsAllowedForProfile(profile))
     return nullptr;
 
+  if (is_sync_test_) {
+    sync_test_app_instance_holders_[context].reset(
+        new arc::InstanceHolder<arc::mojom::AppInstance>());
+    return ArcAppListPrefs::Create(
+        profile, sync_test_app_instance_holders_[context].get());
+  }
+
   arc::ArcBridgeService* bridge_service = arc::ArcBridgeService::Get();
   if (!bridge_service)
     return nullptr;