[iOS Clean] Added dialogs UI support.

ios/clean/chrome/browser/ui/dialogs/dialog_consumer.h

+// Copyright 2017 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_CLEAN_CHROME_BROWSER_UI_DIALOGS_DIALOG_CONSUMER_H_
+#define IOS_CLEAN_CHROME_BROWSER_UI_DIALOGS_DIALOG_CONSUMER_H_
+
+#import <Foundation/Foundation.h>
+
+@class DialogButtonConfiguration;
+@class DialogTextFieldConfiguration;
+
+// A DialogConsumer uses data provided by this protocol to configure and run a
+// dialog.  A DialogConsumer can be configured multiple times before
+// presentation, but once the consumer is presented, the appearance of the
+// dialog will be immutable.
+@protocol DialogConsumer<NSObject>
+
+// Sets the title of the dialog.
+- (void)setDialogTitle:(NSString*)title;
+
+// Sets the message of the dialog.
+- (void)setDialogMessage:(NSString*)message;
+
+// Sets the button items to display in the dialog.
+- (void)setDialogButtonConfigurations:
+    (NSArray<DialogButtonConfiguration*>*)buttonConfigs;
+
+// Sets the text field items to display in the dialog.
+- (void)setDialogTextFieldConfigurations:
+    (NSArray<DialogTextFieldConfiguration*>*)textFieldConfigs;
+
+@end
+
+#endif  // IOS_CLEAN_CHROME_BROWSER_UI_DIALOGS_DIALOG_CONSUMER_H_