Display serial_number for disabled device

If the device is disabled, it can be brought back to life only by the
admin of the domain. And to re-enable the device, admin needs the serial
number which might not match the data displayed on the sticker. Or the
sticker could be damaged. This change will provide the serial number on
the disabled device screen.

BUG=chromium:852284
TEST=Unit tests

Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: I3fe38afc59d7c08ffc175c723b1a37660d8b1160
Reviewed-on: https://chromium-review.googlesource.com/1101209Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Commit-Queue: Igor <igorcov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569218}

chrome/app/chromeos_strings.grdp

@@ -3506,10 +3506,10 @@
     Locked
   </message>
   <message name="IDS_DEVICE_DISABLED_EXPLANATION_WITH_DOMAIN" desc="Explanation shown to the user when the device has been disabled by its owner. This version is used when the domain that owns the device is known.">
-    This device was locked by the <ph name="SAML_DOMAIN">$1<ex>example.com</ex></ph> administrator.
+    This device (SN: <ph name="SERIAL_NUMBER">$1<ex>1234</ex></ph>) was locked by the <ph name="SAML_DOMAIN">$2<ex>example.com</ex></ph> administrator.
   </message>
   <message name="IDS_DEVICE_DISABLED_EXPLANATION_WITHOUT_DOMAIN" desc="Explanation shown to the user when the device has been disabled by its owner. This version is used when the domain that owns the device is not known.">
-    This device was locked by the owner.
+    This device (SN: <ph name="SERIAL_NUMBER">$1<ex>1234</ex></ph>) was locked by the owner.
   </message>
 
   <!-- Encryption migration dialog -->

chrome/browser/chromeos/login/screens/device_disabled_screen.cc

@@ -61,6 +61,10 @@ const std::string& DeviceDisabledScreen::GetMessage() const {
   return device_disabling_manager_->disabled_message();
 }
 
+const std::string& DeviceDisabledScreen::GetSerialNumber() const {
+  return device_disabling_manager_->serial_number();
+}
+
 void DeviceDisabledScreen::OnDisabledMessageChanged(
     const std::string& disabled_message) {
   if (view_)

chrome/browser/chromeos/login/screens/device_disabled_screen.h

@@ -35,6 +35,7 @@ class DeviceDisabledScreen : public BaseScreen,
   void OnViewDestroyed(DeviceDisabledScreenView* view) override;
   const std::string& GetEnrollmentDomain() const override;
   const std::string& GetMessage() const override;
+  const std::string& GetSerialNumber() const override;
 
   // system::DeviceDisablingManager::Observer:
   void OnDisabledMessageChanged(const std::string& disabled_message) override;

chrome/browser/chromeos/login/screens/device_disabled_screen_view.h

@@ -27,6 +27,9 @@ class DeviceDisabledScreenView {
 
     // Returns the message that should be shown to the user.
     virtual const std::string& GetMessage() const = 0;
+
+    // Returns the device serial number that should be shown to the user.
+    virtual const std::string& GetSerialNumber() const = 0;
   };
 
   constexpr static OobeScreen kScreenId = OobeScreen::SCREEN_DEVICE_DISABLED;

chrome/browser/chromeos/system/device_disabling_manager.cc

@@ -18,6 +18,7 @@
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/settings/cros_settings_names.h"
 #include "chromeos/settings/cros_settings_provider.h"
+#include "chromeos/system/statistics_provider.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/prefs/pref_service.h"
 #include "components/user_manager/user_manager.h"
@@ -132,6 +133,10 @@ void DeviceDisablingManager::CheckWhetherDeviceDisabledDuringOOBE(
           policy::kDeviceStateManagementDomain,
           &enrollment_domain_);
 
+  // Update the serial number.
+  serial_number_ = chromeos::system::StatisticsProvider::GetInstance()
+                       ->GetEnterpriseMachineID();
+
   // Update the disabled message.
   std::string disabled_message;
   g_browser_process->local_state()->GetDictionary(
@@ -231,6 +236,10 @@ void DeviceDisablingManager::UpdateFromCrosSettings() {
   enrollment_domain_ =
       browser_policy_connector_->GetEnterpriseEnrollmentDomain();
 
+  // Cache the device serial number.
+  serial_number_ = chromeos::system::StatisticsProvider::GetInstance()
+                       ->GetEnterpriseMachineID();
+
   // If no session or login is in progress, show the device disabled screen.
   delegate_->ShowDeviceDisabledScreen();
 }

chrome/browser/chromeos/system/device_disabling_manager.h

@@ -58,7 +58,7 @@ class DeviceDisablingManager {
     virtual ~Observer();
 
     virtual void OnDisabledMessageChanged(
-     const std::string& disabled_message) = 0;
+        const std::string& disabled_message) = 0;
 
    private:
     DISALLOW_ASSIGN(Observer);
@@ -99,6 +99,10 @@ class DeviceDisablingManager {
   // up to date if the disabled screen was triggered.
   const std::string& disabled_message() const { return disabled_message_; }
 
+  // Returns the cached serial_number. The value is only guaranteed to be
+  // up to date if the disabled screen was triggered.
+  const std::string& serial_number() const { return serial_number_; }
+
   // Performs a check whether the device is disabled during OOBE. |callback|
   // will be invoked with the result of the check.
   void CheckWhetherDeviceDisabledDuringOOBE(
@@ -141,6 +145,9 @@ class DeviceDisablingManager {
   // A cached copy of the message to show on the device disabled screen.
   std::string disabled_message_;
 
+  // A cached copy of the serial number to show on the device disabled screen.
+  std::string serial_number_;
+
   base::WeakPtrFactory<DeviceDisablingManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceDisablingManager);

chrome/browser/chromeos/system/device_disabling_manager_unittest.cc

@@ -22,6 +22,7 @@
 #include "chrome/test/base/testing_browser_process.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/dbus/fake_session_manager_client.h"
+#include "chromeos/system/fake_statistics_provider.h"
 #include "components/ownership/mock_owner_key_util.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/policy/proto/device_management_backend.pb.h"
@@ -81,12 +82,14 @@ class DeviceDisablingManagerTestBase : public testing::Test,
   chromeos::ScopedTestCrosSettings test_cros_settings_;
   chromeos::FakeChromeUserManager fake_user_manager_;
   std::unique_ptr<DeviceDisablingManager> device_disabling_manager_;
+  FakeStatisticsProvider statistics_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceDisablingManagerTestBase);
 };
 
 DeviceDisablingManagerTestBase::DeviceDisablingManagerTestBase()
     : install_attributes_(ScopedStubInstallAttributes::CreateUnset()) {
+  system::StatisticsProvider::SetTestProvider(&statistics_provider_);
 }
 
 void DeviceDisablingManagerTestBase::TearDown() {
@@ -150,6 +153,7 @@ class DeviceDisablingManagerOOBETest : public DeviceDisablingManagerTestBase {
   void OnDeviceDisabledChecked(bool device_disabled);
 
   TestingPrefServiceSimple local_state_;
+  FakeStatisticsProvider statistics_provider_;
 
   base::RunLoop run_loop_;
   bool device_disabled_;
@@ -168,6 +172,7 @@ void DeviceDisablingManagerOOBETest::SetUp() {
   policy::DeviceCloudPolicyManagerChromeOS::RegisterPrefs(
       local_state_.registry());
   CreateDeviceDisablingManager();
+  system::StatisticsProvider::SetTestProvider(&statistics_provider_);
 }
 
 void DeviceDisablingManagerOOBETest::TearDown() {

chrome/browser/resources/chromeos/login/screen_device_disabled.js

@@ -8,7 +8,7 @@
 
 login.createScreen('DeviceDisabledScreen', 'device-disabled', function() {
   return {
-    EXTERNAL_API: ['setEnrollmentDomain', 'setMessage'],
+    EXTERNAL_API: ['setSerialNumberAndEnrollmentDomain', 'setMessage'],
 
     /**
      * Ignore any accelerators the user presses on this screen.
@@ -17,7 +17,7 @@ login.createScreen('DeviceDisabledScreen', 'device-disabled', function() {
 
     /** @override */
     decorate: function() {
-      this.setEnrollmentDomain(null);
+      this.setSerialNumberAndEnrollmentDomain('', null);
     },
 
     /**
@@ -42,21 +42,24 @@ login.createScreen('DeviceDisabledScreen', 'device-disabled', function() {
 
     /**
      * Updates the explanation shown to the user. The explanation will indicate
-     * that the device is owned by |enrollment_domain|. If |enrollment_domain|
-     * is null or empty, a generic explanation will be used instead that does
-     * not reference any domain.
+     * the device serial number and that it is owned by |enrollment_domain|. If
+     * |enrollment_domain| is null or empty, a generic explanation will be used
+     * instead that does not reference any domain.
+     * @param {string} serial_number The serial number of the device.
      * @param {string} enrollment_domain The domain that owns the device.
      */
-    setEnrollmentDomain: function(enrollment_domain) {
+    setSerialNumberAndEnrollmentDomain: function(
+        serial_number, enrollment_domain) {
       if (enrollment_domain) {
         // The contents of |enrollment_domain| is untrusted. Set the resulting
         // string as |textContent| so that it gets treated as plain text and
         // cannot be used to inject JS or HTML.
         $('device-disabled-explanation').textContent = loadTimeData.getStringF(
-            'deviceDisabledExplanationWithDomain', enrollment_domain);
+            'deviceDisabledExplanationWithDomain', serial_number,
+            enrollment_domain);
       } else {
-        $('device-disabled-explanation').textContent =
-            loadTimeData.getString('deviceDisabledExplanationWithoutDomain');
+        $('device-disabled-explanation').textContent = loadTimeData.getStringF(
+            'deviceDisabledExplanationWithoutDomain', serial_number);
       }
     },
 

chrome/browser/ui/webui/chromeos/login/device_disabled_screen_handler.cc

@@ -34,7 +34,8 @@ void DeviceDisabledScreenHandler::Show() {
   }
 
   if (delegate_) {
-    CallJS("setEnrollmentDomain", delegate_->GetEnrollmentDomain());
+    CallJS("setSerialNumberAndEnrollmentDomain", delegate_->GetSerialNumber(),
+           delegate_->GetEnrollmentDomain());
     CallJS("setMessage", delegate_->GetMessage());
   }
   ShowScreen(kScreenId);