arc: Fix race conditon when Play Store is started too early.

chrome/browser/ui/app_list/arc/arc_app_test.h

Index: chrome/browser/ui/app_list/arc/arc_app_test.h
diff --git a/chrome/browser/ui/app_list/arc/arc_app_test.h b/chrome/browser/ui/app_list/arc/arc_app_test.h
index 8163acd7ff51dcd358fd6fc302f6423ffb11d30b..db1fa73c07bab4faa2be95afc40fb3f0753cdde4 100644
--- a/chrome/browser/ui/app_list/arc/arc_app_test.h
+++ b/chrome/browser/ui/app_list/arc/arc_app_test.h
@@ -59,6 +59,8 @@ class ArcAppTest {
 
   void RemovePackage(const arc::mojom::ArcPackageInfo& package);
 
+  void WaitForDefaultApps();
+
   // The 0th item is sticky but not the followings.
   const std::vector<arc::mojom::AppInfo>& fake_apps() const {
     return fake_apps_;
@@ -85,6 +87,10 @@ class ArcAppTest {
     return arc_service_manager_.get();
   }
 
+  void set_wait_default_apps(bool wait_default_apps) {
+    wait_default_apps_ = wait_default_apps;
+  }
+
  private:
   const user_manager::User* CreateUserAndLogin();
   bool FindPackage(const arc::mojom::ArcPackageInfo& package);
@@ -95,6 +101,8 @@ class ArcAppTest {
 
   ArcAppListPrefs* arc_app_list_pref_ = nullptr;
 
+  bool wait_default_apps_ = true;
+
   std::unique_ptr<arc::ArcServiceManager> arc_service_manager_;
   std::unique_ptr<arc::ArcSessionManager> arc_session_manager_;
   std::unique_ptr<arc::ArcPlayStoreEnabledPreferenceHandler>