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

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

Index: chrome/browser/ui/app_list/arc/arc_app_test.cc
diff --git a/chrome/browser/ui/app_list/arc/arc_app_test.cc b/chrome/browser/ui/app_list/arc/arc_app_test.cc
index 94ad8c212e71cd38e092189eb1a0664089270df4..8fb88d3a698acb2d1e1a0c890aaf8fdaaff3e0f4 100644
--- a/chrome/browser/ui/app_list/arc/arc_app_test.cc
+++ b/chrome/browser/ui/app_list/arc/arc_app_test.cc
@@ -97,9 +97,8 @@ void ArcAppTest::SetUp(Profile* profile) {
 
   arc_app_list_pref_ = ArcAppListPrefs::Get(profile_);
   DCHECK(arc_app_list_pref_);
-  base::RunLoop run_loop;
-  arc_app_list_pref_->SetDefaltAppsReadyCallback(run_loop.QuitClosure());
-  run_loop.Run();
+  if (wait_default_apps_)
+    WaitForDefaultApps();
 
   // Check initial conditions.
   if (arc::ShouldArcAlwaysStart()) {
@@ -115,6 +114,13 @@ void ArcAppTest::SetUp(Profile* profile) {
       app_instance_.get());
 }
 
+void ArcAppTest::WaitForDefaultApps() {
+  DCHECK(arc_app_list_pref_);
+  base::RunLoop run_loop;
+  arc_app_list_pref_->SetDefaltAppsReadyCallback(run_loop.QuitClosure());
+  run_loop.Run();
+}
+
 void ArcAppTest::CreateFakeAppsAndPackages() {
   arc::mojom::AppInfo app;
   // Make sure we have enough data for test.