Remove demo mode resources when a user logs in on a managed device

Device getting enterprise enrolled, and then used should be a good
signal that demo mode resources are no longer needed.

An exception is made for demo mode implemented through public sessions
(as it's the case today) - in that case retailer might attempt to swich
to the revamped demo mode sessions, so might need the resources after
all.

BUG=827368

Change-Id: Ia5645b059050f9d7858ba34acd84201969b88b71
Reviewed-on: https://chromium-review.googlesource.com/1176652
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584222}

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

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/login/demo_mode/demo_mode_resources_remover.h"
 
+#include <memory>
 #include <utility>
 
 #include "base/files/file_path.h"
@@ -13,10 +14,19 @@
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/task/post_task.h"
+#include "base/values.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/browser_process_platform_part.h"
+#include "chrome/browser/chromeos/login/demo_mode/demo_app_launcher.h"
 #include "chrome/browser/chromeos/login/demo_mode/demo_session.h"
+#include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
+#include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
+#include "components/user_manager/user.h"
+#include "components/user_manager/user_type.h"
+#include "third_party/re2/src/re2/re2.h"
 
 namespace chromeos {
 
@@ -28,6 +38,14 @@ DemoModeResourcesRemover* g_instance = nullptr;
 // have been removed from the device.
 constexpr char kDemoModeResourcesRemoved[] = "demo_mode_resources_removed";
 
+// Regex matching legacy demo retail mode domains.
+constexpr char kLegacyDemoRetailModeDomainRegex[] =
+    "[[:alpha:]]{2}-retailmode.com";
+
+// An extra legacy demo retail mode domain that does not match
+// |kLegacyDemoRetailModeDomainRegex|.
+constexpr char kExtraLegacyDemoRetailModeDomain[] = "us2-retailmode.com";
+
 // Deletes directory at |path| from the device.
 DemoModeResourcesRemover::RemovalResult RemoveDirectory(
     const base::FilePath& path) {
@@ -40,6 +58,22 @@ DemoModeResourcesRemover::RemovalResult RemoveDirectory(
   return DemoModeResourcesRemover::RemovalResult::kSuccess;
 }
 
+// Tests whether the session with user |user| is part of legacy demo mode -
+// a public session in a legacy demo retail mode domain.
+// Note that DemoSession::IsDeviceInDemoMode will return false for these
+// sessions.
+bool IsLegacyDemoRetailModeSession(const user_manager::User* user) {
+  if (user->GetType() != user_manager::USER_TYPE_PUBLIC_ACCOUNT)
+    return false;
+
+  const std::string enrollment_domain =
+      g_browser_process->platform_part()
+          ->browser_policy_connector_chromeos()
+          ->GetEnterpriseEnrollmentDomain();
+  return DemoModeResourcesRemover::IsLegacyDemoRetailModeDomain(
+      enrollment_domain);
+}
+
 }  // namespace
 
 // static
@@ -64,15 +98,46 @@ DemoModeResourcesRemover* DemoModeResourcesRemover::Get() {
   return g_instance;
 }
 
+// static
+bool DemoModeResourcesRemover::IsLegacyDemoRetailModeDomain(
+    const std::string& domain) {
+  return RE2::FullMatch(domain, kLegacyDemoRetailModeDomainRegex) ||
+         domain == kExtraLegacyDemoRetailModeDomain;
+}
+
 DemoModeResourcesRemover::~DemoModeResourcesRemover() {
   CHECK_EQ(g_instance, this);
   g_instance = nullptr;
+
+  ChromeUserManager::Get()->RemoveSessionStateObserver(this);
 }
 
 void DemoModeResourcesRemover::LowDiskSpace(uint64_t free_disk_space) {
   AttemptRemoval(RemovalReason::kLowDiskSpace, RemovalCallback());
 }
 
+void DemoModeResourcesRemover::ActiveUserChanged(
+    const user_manager::User* user) {
+  // Ignore user activity in guest sessions.
+  if (user->GetType() == user_manager::USER_TYPE_GUEST)
+    return;
+
+  // Do not remove resources if the device is in a legacy derelict demo session,
+  // which is implemented as kiosk - note that this is different than sessions
+  // detected by IsLegacyDemoRetailModeSession().
+  if (DemoAppLauncher::IsDemoAppSession(user->GetAccountId()))
+    return;
+
+  // Attempt resources removal if the device is managed, and not in a retail
+  // mode domain.
+  if (g_browser_process->platform_part()
+          ->browser_policy_connector_chromeos()
+          ->IsEnterpriseManaged() &&
+      !IsLegacyDemoRetailModeSession(user)) {
+    AttemptRemoval(RemovalReason::kEnterpriseEnrolled, RemovalCallback());
+  }
+}
+
 void DemoModeResourcesRemover::AttemptRemoval(RemovalReason reason,
                                               RemovalCallback callback) {
   if (local_state_->GetBoolean(kDemoModeResourcesRemoved)) {
@@ -115,6 +180,7 @@ DemoModeResourcesRemover::DemoModeResourcesRemover(PrefService* local_state)
   g_instance = this;
 
   cryptohome_observer_.Add(DBusThreadManager::Get()->GetCryptohomeClient());
+  ChromeUserManager::Get()->AddSessionStateObserver(this);
 }
 
 void DemoModeResourcesRemover::OnRemovalDone(RemovalResult result) {
@@ -124,6 +190,7 @@ void DemoModeResourcesRemover::OnRemovalDone(RemovalResult result) {
   if (result == RemovalResult::kNotFound || result == RemovalResult::kSuccess) {
     local_state_->SetBoolean(kDemoModeResourcesRemoved, true);
     cryptohome_observer_.RemoveAll();
+    ChromeUserManager::Get()->RemoveSessionStateObserver(this);
   }
 
   UMA_HISTOGRAM_ENUMERATION("DemoMode.ResourcesRemoval.Result", result);

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

@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_CHROMEOS_LOGIN_DEMO_MODE_DEMO_MODE_RESOURCES_REMOVER_H_
 
 #include <memory>
+#include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
@@ -13,6 +14,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "chromeos/dbus/cryptohome_client.h"
+#include "components/user_manager/user_manager.h"
 
 class PrefRegistrySimple;
 class PrefService;
@@ -28,10 +30,12 @@ namespace chromeos {
 // Demo mode resources are deleted if the device is not in demo mode, and any
 // of the following conditions are satisfied:
 //   * device is running low on disk space
-//   * TODO(crbug.com/827368): device is enrolled in a non-demo-mode domain
+//   * device is enrolled in a non-demo-mode domain
 //   * TODO(crbug.com/827368): enough non-demo-mode user activity has been
 //     detected on the device
-class DemoModeResourcesRemover : public CryptohomeClient::Observer {
+class DemoModeResourcesRemover
+    : public CryptohomeClient::Observer,
+      public user_manager::UserManager::UserSessionStateObserver {
  public:
   // The reason a removal was requested.
   // DO NOT REORDER - used to report metrics.
@@ -85,11 +89,21 @@ class DemoModeResourcesRemover : public CryptohomeClient::Observer {
   static std::unique_ptr<DemoModeResourcesRemover> CreateIfNeeded(
       PrefService* local_state);
 
+  // Method used to determine whether a domain is associated with legacy demo
+  // retail mode, where demo mode sessions are implemented as public sessions.
+  // Exposed so the matching can be tested.
+  // TODO(crbug.com/874778): Remove after legacy retail mode domains have been
+  // disabled.
+  static bool IsLegacyDemoRetailModeDomain(const std::string& domain);
+
   ~DemoModeResourcesRemover() override;
 
   // CryptohomeClient::Observer:
   void LowDiskSpace(uint64_t free_disk_space) override;
 
+  // user_manager::UserManager::UserSessionStateObserver:
+  void ActiveUserChanged(const user_manager::User* user) override;
+
   // Requests demo mode resources removal from the disk. If a removal operation
   // is already in progress, this method will schedule the callback to be run
   // with the result of the operation in progress.