[iOS Clean] Added HTTP authentication dialog support.

ios/clean/chrome/browser/ui/dialogs/http_auth_dialogs/http_auth_dialog_request.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_HTTP_AUTH_DIALOGS_HTTP_AUTH_DIALOG_REQUEST_H_
+#define IOS_CLEAN_CHROME_BROWSER_UI_DIALOGS_HTTP_AUTH_DIALOGS_HTTP_AUTH_DIALOG_REQUEST_H_
+
+#import <Foundation/Foundation.h>
+
+namespace web {
+class WebState;
+}
+
+// Block type for HTTP authentication callbacks.
+typedef void (^HTTPAuthDialogCallback)(NSString* username, NSString* password);
+
+// A container object encapsulating all the state necessary to support an
+// HTTPAuthDialogCoordiantor.  This object also owns the WebKit
+// completion block that will throw an exception if it is deallocated before
+// being executed. |-runCallbackWithUserName:password:| must be executed once in
+// the lifetime of every HTTPAuthDialogRequest.
+@interface HTTPAuthDialogRequest : NSObject
+
+// Factory method to create HTTPAuthDialogRequests from the given input.  All
+// arguments to this function are expected to be nonnull.
++ (instancetype)stateWithWebState:(web::WebState*)webState
+                  protectionSpace:(NSURLProtectionSpace*)protectionSpace
+                       credential:(NSURLCredential*)credential
+                         callback:(HTTPAuthDialogCallback)callback;
+
+// The WebState displaying this dialog.
+@property(nonatomic, readonly) web::WebState* webState;
+
+// The title to use for the dialog.
+@property(nonatomic, readonly, strong) NSString* title;
+
+// The authentication message for the dialog's protection space.
+@property(nonatomic, readonly, strong) NSString* message;
+
+// The default text to display in the username text field.
+@property(nonatomic, readonly, strong) NSString* defaultUserNameText;
+
+// Completes the HTTP authentication flow with the given username and password.
+// If the user taps the OK button, |username| and |password| are expected to be
+// non-nil, even if they are empty strings.  If the user taps the Cancel button,
+// arguments should be nil.
+- (void)completeAuthenticationWithUsername:(NSString*)username
+                                  password:(NSString*)password;
+
+@end
+
+#endif  // IOS_CLEAN_CHROME_BROWSER_UI_DIALOGS_HTTP_AUTH_DIALOGS_HTTP_AUTH_DIALOG_REQUEST_H_