Upstream Chrome on iOS source code [6/11].

ios/chrome/browser/ui/qr_scanner/qr_scanner_alerts.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_QR_SCANNER_QR_SCANNER_ALERTS_H_
+#define IOS_CHROME_BROWSER_UI_QR_SCANNER_QR_SCANNER_ALERTS_H_
+
+#include "ios/chrome/browser/ui/qr_scanner/camera_controller.h"
+
+@class UIAlertAction;
+@class UIAlertController;
+
+namespace qr_scanner {
+
+// Block type that takes a UIAlertAction. Blocks of this type will be called
+// when the Cancel button of a UIAlertView is pressed.
+typedef void (^CancelAlertAction)(UIAlertAction* alertAction);
+
+// Returns a dialog to be displayed when the camera state is |state|.
+// |cancelBlock| is executed when the button to close the dialog is tapped. If
+// |cancelBlock| is nil, the dialog is dismissed on cancel.
+UIAlertController* DialogForCameraState(CameraState state,
+                                        CancelAlertAction cancelBlock);
+
+}  // namespace qr_scanner
+
+#endif  // IOS_CHROME_BROWSER_UI_QR_SCANNER_QR_SCANNER_ALERTS_H_