Allow Play Store to be visible to child accounts when ARC++ is disabled.

Bug: 898676
Change-Id: Id2c15af3c517ceffe919d5baa1955c00392c9307
Reviewed-on: https://chromium-review.googlesource.com/c/1298302Reviewed-by: Yury Khmel <khmel@chromium.org>
Commit-Queue: Bruno Santos <brunoad@google.com>
Cr-Commit-Position: refs/heads/master@{#603964}

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

@@ -856,10 +856,16 @@ void ArcAppListPrefs::SetDefaultAppsFilterLevel() {
   // Match this requirement and don't show pre-installed apps for managed users
   // in app list.
   if (arc::policy_util::IsAccountManaged(profile_)) {
-    default_apps_->set_filter_level(
-        arc::IsArcPlayStoreEnabledForProfile(profile_)
-            ? ArcDefaultAppList::FilterLevel::OPTIONAL_APPS
-            : ArcDefaultAppList::FilterLevel::ALL);
+    if (profile_->IsChild()) {
+      // For child accounts, filter only optional apps.
+      default_apps_->set_filter_level(
+          ArcDefaultAppList::FilterLevel::OPTIONAL_APPS);
+    } else {
+      default_apps_->set_filter_level(
+          arc::IsArcPlayStoreEnabledForProfile(profile_)
+              ? ArcDefaultAppList::FilterLevel::OPTIONAL_APPS
+              : ArcDefaultAppList::FilterLevel::ALL);
+    }
   } else {
     default_apps_->set_filter_level(ArcDefaultAppList::FilterLevel::NOTHING);
   }