[iOS] Add FakeAlertConsumer.

This allows for testing of mediators that set up AlertViewControllers.

Bug: 941745
Change-Id: I103f40000d3a9714ba782c41fbf2976263122728
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1636397
Commit-Queue: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664797}

ios/chrome/browser/ui/alert_view_controller/test/BUILD.gn

+# Copyright 2019 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.
+
+source_set("test") {
+  testonly = true
+  sources = [
+    "fake_alert_consumer.h",
+    "fake_alert_consumer.mm",
+  ]
+
+  configs += [ "//build/config/compiler:enable_arc" ]
+
+  deps = [
+    "//base",
+    "//ios/chrome/browser/ui/alert_view_controller",
+    "//testing/gtest",
+  ]
+}

ios/chrome/browser/ui/alert_view_controller/test/fake_alert_consumer.h

+// Copyright 2019 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_ALERT_VIEW_CONTROLLER_TEST_FAKE_ALERT_CONSUMER_H_
+#define IOS_CHROME_BROWSER_UI_ALERT_VIEW_CONTROLLER_TEST_FAKE_ALERT_CONSUMER_H_
+
+#import "ios/chrome/browser/ui/alert_view_controller/alert_consumer.h"
+
+// Fake version of AlertConsumer that allows read access to consumed values.
+@interface FakeAlertConsumer : NSObject <AlertConsumer>
+
+@property(nonatomic, copy) NSString* title;
+@property(nonatomic, copy) NSString* message;
+@property(nonatomic, copy)
+    NSArray<TextFieldConfiguration*>* textFieldConfigurations;
+@property(nonatomic, copy) NSArray<AlertAction*>* actions;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_ALERT_VIEW_CONTROLLER_TEST_FAKE_ALERT_CONSUMER_H_

ios/chrome/browser/ui/alert_view_controller/test/fake_alert_consumer.mm

+// Copyright 2019 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.
+
+#import "ios/chrome/browser/ui/alert_view_controller/test/fake_alert_consumer.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@implementation FakeAlertConsumer
+@end