DLP: Show notification when video screen capture is interrupted.

According to the latest UX mocks, when the running video screen capture
is interrupted due to confidential content that appears in the captured area
a corresponding notification should be shown to the user.
See mocks: https://docs.google.com/presentation/d/1v0GM-lwHCznFJ6hnZlUH37eBOuAkJMw5Q6UnSkcKOgA/edit?hl=en#slide=id.ga41d6e7481_4_0

Bug: 1133324
Change-Id: Ibde37d0d5980b2ebe67f5b69cc2ab3f96e4fab99
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2502341
Commit-Queue: Sergey Poromov <poromov@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821684}

ash/ash_strings.grd

@@ -2955,12 +2955,18 @@ Here are some things you can try to get started.
       <message name="IDS_ASH_SCREEN_CAPTURE_FAILURE_TITLE" desc="The title of the notification when capture mode fails.">
         An error occurred
       </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_STOPPED_TITLE" desc="The title of the notification when video capture is stopped.">
+        Screen recording stopped
+      </message>
       <message name="IDS_ASH_SCREEN_CAPTURE_DISABLED_MESSAGE" desc="The text of the notification when capture mode is disabled.">
         The ability to screen capture has been disabled by your administrator.
       </message>
       <message name="IDS_ASH_SCREEN_CAPTURE_FAILURE_MESSAGE" desc="The text of the notification when capture mode fails.">
         Failed to capture screen
       </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_STOPPED_MESSAGE" desc="The text of the notification when video capture is stopped.">
+        Screen recording stopped due to confidential content on your screen.
+      </message>
       <message name="IDS_ASH_SCREEN_CAPTURE_DISPLAY_SOURCE" desc="The name that is the display source of the screen capture notification.">
         Screen capture
       </message>

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_STOPPED_MESSAGE.png.sha1

+feb4ffe52e5331898d157388837de87b11285126
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_STOPPED_TITLE.png.sha1

+feb4ffe52e5331898d157388837de87b11285126
\ No newline at end of file

ash/capture_mode/capture_mode_controller.cc

@@ -33,6 +33,7 @@
 #include "base/task/thread_pool.h"
 #include "base/time/time.h"
 #include "components/prefs/pref_service.h"
+#include "components/vector_icons/vector_icons.h"
 #include "ui/base/clipboard/clipboard_data.h"
 #include "ui/base/clipboard/clipboard_non_backed.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -48,6 +49,8 @@ namespace {
 CaptureModeController* g_instance = nullptr;
 
 constexpr char kScreenCaptureNotificationId[] = "capture_mode_notification";
+constexpr char kScreenCaptureStoppedNotificationId[] =
+    "capture_mode_stopped_notification";
 constexpr char kScreenCaptureNotifierId[] = "ash.capture_mode_controller";
 
 // The format strings of the file names of captured images.
@@ -182,6 +185,25 @@ void ShowFailureNotification() {
       /*optional_fields=*/{}, /*delegate=*/nullptr);
 }
 
+// Shows a notification informing the user that video recording was stopped.
+void ShowVideoRecordingStoppedNotification() {
+  std::unique_ptr<message_center::Notification> notification =
+      CreateSystemNotification(
+          message_center::NOTIFICATION_TYPE_SIMPLE,
+          kScreenCaptureStoppedNotificationId,
+          l10n_util::GetStringUTF16(IDS_ASH_SCREEN_CAPTURE_STOPPED_TITLE),
+          l10n_util::GetStringUTF16(IDS_ASH_SCREEN_CAPTURE_STOPPED_MESSAGE),
+          /*display_source=*/base::string16(), GURL(),
+          message_center::NotifierId(
+              message_center::NotifierType::SYSTEM_COMPONENT,
+              kScreenCaptureNotifierId),
+          /*optional_fields=*/{}, /*delegate=*/nullptr,
+          vector_icons::kBusinessIcon,
+          message_center::SystemNotificationWarningLevel::CRITICAL_WARNING);
+  message_center::MessageCenter::Get()->AddNotification(
+      std::move(notification));
+}
+
 // Copies the bitmap representation of the given |image| to the clipboard.
 void CopyImageToClipboard(const gfx::Image& image) {
   auto* clipboard = ui::ClipboardNonBacked::GetForCurrentThread();
@@ -586,10 +608,15 @@ void CaptureModeController::OnVideoRecordCountDownFinished() {
 
   delegate_->StartObservingRestrictedContent(
       capture_params->window, capture_params->bounds,
-      base::BindOnce(&CaptureModeController::EndVideoRecording,
+      base::BindOnce(&CaptureModeController::InterruptVideoRecording,
                      weak_ptr_factory_.GetWeakPtr()));
 
   ShowStopRecordingButton(capture_params->window->GetRootWindow());
 }
 
+void CaptureModeController::InterruptVideoRecording() {
+  ShowVideoRecordingStoppedNotification();
+  EndVideoRecording();
+}
+
 }  // namespace ash

ash/capture_mode/capture_mode_controller.h

@@ -154,6 +154,10 @@ class ASH_EXPORT CaptureModeController {
   // Called when the video record 3-seconds count down finishes.
   void OnVideoRecordCountDownFinished();
 
+  // Called to interrupt the ongoing video recording because it's not anymore
+  // allowed to be captured.
+  void InterruptVideoRecording();
+
   std::unique_ptr<CaptureModeDelegate> delegate_;
 
   CaptureModeType type_ = CaptureModeType::kImage;