Creates coordinators for displaying alerts

ios/chrome/browser/ui/alert_coordinator/action_sheet_coordinator.mm

Index: ios/chrome/browser/ui/alert_coordinator/action_sheet_coordinator.mm
diff --git a/ios/chrome/browser/ui/alert_coordinator/action_sheet_coordinator.mm b/ios/chrome/browser/ui/alert_coordinator/action_sheet_coordinator.mm
new file mode 100644
index 0000000000000000000000000000000000000000..443727449236b40e4560bd12549de6fb85d48f61
--- /dev/null
+++ b/ios/chrome/browser/ui/alert_coordinator/action_sheet_coordinator.mm
@@ -0,0 +1,57 @@
+// 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.
+
+#import "ios/chrome/browser/ui/alert_coordinator/action_sheet_coordinator.h"
+
+#import "base/ios/weak_nsobject.h"
+#import "base/mac/scoped_nsobject.h"
+#import "ios/chrome/browser/ui/alert_coordinator/alert_controller_coordinator+subclassing.h"
+#import "ios/web/public/web_state/context_menu_params.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/strings/grit/ui_strings.h"
+
+@interface ActionSheetCoordinator () {
+  // Parameters that define what is shown in the context menu.
+  web::ContextMenuParams _params;

[lpromero, 2016/07/06 09:03:59]

// weak?

[gambard, 2016/07/07 08:57:42]

It is not pointer. Should it be weak?

+}
+
+@end
+
+@implementation ActionSheetCoordinator
+
+- (instancetype)initWithViewController:(UIViewController*)viewController
+                                params:(const web::ContextMenuParams&)params {
+  self = [super initWithBaseViewController:viewController];
+  if (self) {
+    _params = params;
+  }
+  return self;
+}
+
+#pragma mark - Private Methods
+
+- (BOOL)shouldStart {
+  // Check that the view is still visible on screen, otherwise just return and
+  // don't show the context menu.
+  return [_params.view window] || [_params.view isKindOfClass:[UIWindow class]];
+}
+
+- (UIAlertController*)createAlertController {
+  DCHECK([_params.view isDescendantOfView:[self.baseViewController view]]);
+  UIAlertController* alert = [UIAlertController
+      alertControllerWithTitle:_params.menu_title
+                       message:self.message
+                preferredStyle:UIAlertControllerStyleActionSheet];
+  alert.popoverPresentationController.sourceView = _params.view;
+  alert.popoverPresentationController.sourceRect =
+      CGRectMake(_params.location.x, _params.location.y, 1.0, 1.0);
+
+  return alert;

[lpromero, 2016/07/06 09:03:58]

If renamed newAlertController, you need to return [alert retain].

[gambard, 2016/07/07 08:57:42]

Acknowledged.

+}
+
+- (BOOL)shouldCreateCancelButtonAtCreation {
+  return YES;
+}
+
+@end