Use PathService to determine demo mode resources path

Updates chromeos::DemoSession to use
chromeos::DIR_PREINSTALLED_COMPONENTS to determine the preinstalled demo
mode resources path.

TEST=existing unittests
BUG=869455

Change-Id: Idd63ae0893b4fa3966d69bb295fbdb0290456bca
Reviewed-on: https://chromium-review.googlesource.com/1180729
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585373}

chrome/browser/chromeos/login/demo_mode/demo_mode_resources_remover_unittest.cc

@@ -13,15 +13,14 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
 #include "base/optional.h"
-#include "base/test/scoped_task_environment.h"
+#include "base/test/scoped_path_override.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/login/demo_mode/demo_session.h"
 #include "chrome/browser/chromeos/login/users/fake_chrome_user_manager.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/chromeos/settings/stub_install_attributes.h"
-#include "chrome/browser/extensions/external_policy_loader.h"
-#include "chrome/test/base/testing_profile.h"
+#include "chromeos/chromeos_paths.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/fake_cryptohome_client.h"
 #include "components/prefs/testing_pref_service.h"
@@ -67,10 +66,11 @@ class DemoModeResourcesRemoverTest : public testing::Test {
         std::move(cryptohome_client));
 
     ASSERT_TRUE(scoped_temp_dir_.CreateUniqueTempDir());
-    demo_resources_path_ =
-        scoped_temp_dir_.GetPath().AppendASCII("demo-mode-resources");
-    DemoSession::OverridePreInstalledDemoResourcesPathForTesting(
-        &demo_resources_path_);
+    components_path_override_ = std::make_unique<base::ScopedPathOverride>(
+        chromeos::DIR_PREINSTALLED_COMPONENTS, scoped_temp_dir_.GetPath());
+    demo_resources_path_ = scoped_temp_dir_.GetPath()
+                               .AppendASCII("cros-components")
+                               .AppendASCII("demo-mode-resources");
 
     scoped_user_manager_ = std::make_unique<user_manager::ScopedUserManager>(
         std::make_unique<FakeChromeUserManager>());
@@ -83,7 +83,6 @@ class DemoModeResourcesRemoverTest : public testing::Test {
 
   void TearDown() override {
     DemoSession::ShutDownIfInitialized();
-    DemoSession::OverridePreInstalledDemoResourcesPathForTesting(nullptr);
     DemoSession::SetDemoModeEnrollmentTypeForTesting(
         DemoSession::EnrollmentType::kNone);
     chromeos::DBusThreadManager::Shutdown();
@@ -190,6 +189,7 @@ class DemoModeResourcesRemoverTest : public testing::Test {
   std::unique_ptr<ScopedStubInstallAttributes> install_attributes_;
 
   base::ScopedTempDir scoped_temp_dir_;
+  std::unique_ptr<base::ScopedPathOverride> components_path_override_;
   base::FilePath demo_resources_path_;
 
   std::unique_ptr<user_manager::ScopedUserManager> scoped_user_manager_;

chrome/browser/chromeos/login/demo_mode/demo_session.cc

@@ -9,6 +9,7 @@
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
+#include "base/path_service.h"
 #include "base/sys_info.h"
 #include "chrome/browser/apps/platform_apps/app_load_service.h"
 #include "chrome/browser/browser_process.h"
@@ -17,6 +18,7 @@
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/settings/install_attributes.h"
 #include "chrome/browser/profiles/profile_manager.h"
+#include "chromeos/chromeos_paths.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/image_loader_client.h"
 #include "components/session_manager/core/session_manager.h"
@@ -35,16 +37,6 @@ DemoSession::EnrollmentType g_force_enrollment_type =
 // The name of the offline demo resource image loader component.
 constexpr char kDemoResourcesComponentName[] = "demo-mode-resources";
 
-// The path from which the offline demo mode resources component should be
-// loaded by the image loader service.
-constexpr base::FilePath::CharType kPreInstalledDemoResourcesComponentPath[] =
-    FILE_PATH_LITERAL(
-        "/mnt/stateful_partition/unencrypted/demo_mode_resources");
-
-// Can be set in test to override location of preinstalled offline resources
-// component path.
-const base::FilePath* g_pre_installed_demo_resources_path_override = nullptr;
-
 // Path relative to the path at which offline demo resources are loaded that
 // contains image with demo Android apps.
 constexpr base::FilePath::CharType kDemoAppsPath[] =
@@ -71,15 +63,11 @@ bool IsDemoModeOfflineEnrolled() {
 
 // static
 base::FilePath DemoSession::GetPreInstalledDemoResourcesPath() {
-  if (g_pre_installed_demo_resources_path_override)
-    return *g_pre_installed_demo_resources_path_override;
-  return base::FilePath(kPreInstalledDemoResourcesComponentPath);
-}
-
-// static
-void DemoSession::OverridePreInstalledDemoResourcesPathForTesting(
-    base::FilePath* overriden_path) {
-  g_pre_installed_demo_resources_path_override = overriden_path;
+  base::FilePath preinstalled_components_root;
+  base::PathService::Get(DIR_PREINSTALLED_COMPONENTS,
+                         &preinstalled_components_root);
+  return preinstalled_components_root.AppendASCII("cros-components")
+      .AppendASCII(kDemoResourcesComponentName);
 }
 
 // static

chrome/browser/chromeos/login/demo_mode/demo_session.h

@@ -44,8 +44,6 @@ class DemoSession : public session_manager::SessionManagerObserver {
   // Location on disk where pre-installed demo mode resources are expected to be
   // found.
   static base::FilePath GetPreInstalledDemoResourcesPath();
-  static void OverridePreInstalledDemoResourcesPathForTesting(
-      base::FilePath* overriden_path);
 
   // Whether the device is set up to run demo sessions.
   static bool IsDeviceInDemoMode();