Fix null profile crash in Gellerization flow

The crash is fixed by null checking the profile, and made further
robust by removing the call to the crashing code and instead
using the AppService's own API for checking whether an app is
a system app, AKA "sticky".

Bug: 1026859
Change-Id: I7da239c74aa18e3bed157a7e0ce3c91cdb1e13bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2216601Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Auto-Submit: Dan S <danan@chromium.org>
Commit-Queue: Dan S <danan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772320}

chrome/browser/ui/webui/chromeos/add_supervision/add_supervision_handler.cc

@@ -55,10 +55,16 @@ void AddSupervisionHandler::RequestClose(RequestCloseCallback callback) {
 void AddSupervisionHandler::GetInstalledArcApps(
     GetInstalledArcAppsCallback callback) {
   Profile* profile = Profile::FromWebUI(web_ui_);
+  if (!profile) {
+    DLOG(WARNING) << "Profile not found in WebUI";
+    std::move(callback).Run({});
+    return;
+  }
+
   apps::AppServiceProxy* proxy =
       apps::AppServiceProxyFactory::GetForProfile(profile);
 
-  if (arc::ArcSessionManager::Get() == nullptr) {
+  if (!arc::ArcSessionManager::Get()) {
     DLOG(WARNING) << "No ArcSessionManager available";
     std::move(callback).Run({});
     return;
@@ -71,15 +77,9 @@ void AddSupervisionHandler::GetInstalledArcApps(
   }
 
   std::vector<std::string> installed_arc_apps;
-
   proxy->AppRegistryCache().ForEachApp(
       [&installed_arc_apps, profile](const apps::AppUpdate& update) {
-        // We don't include "sticky" ARC apps because they are system-required
-        // apps that should not be offered for uninstallation. TODO(danan):
-        // check for stickyness via the App Service instead when that is
-        // available. (https://crbug.com/948408).
-        if (ShouldIncludeAppUpdate(update) &&
-            !arc::IsArcAppSticky(update.AppId(), profile)) {
+        if (ShouldIncludeAppUpdate(update)) {
           std::string package_name =
               arc::AppIdToArcPackageName(update.AppId(), profile);
           if (!package_name.empty())

chrome/browser/ui/webui/chromeos/add_supervision/add_supervision_handler_utils.cc

@@ -13,10 +13,8 @@
 #include "components/services/app_service/public/mojom/types.mojom.h"
 
 bool ShouldIncludeAppUpdate(const apps::AppUpdate& app_update) {
-  // TODO(danan): update this to only return sticky = true arc apps when that
-  // attribute is available via the App Service (https://crbug.com/948408).
-
-  return app_update.AppType() == apps::mojom::AppType::kArc;
+  return app_update.AppType() == apps::mojom::AppType::kArc &&
+         app_update.InstallSource() != apps::mojom::InstallSource::kSystem;
 }
 
 void LogOutHelper() {