Upstream Chrome on iOS source code [2/11].

ios/chrome/browser/tabs/tab_dialog_delegate.h

+// Copyright 2015 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_TABS_TAB_DIALOG_DELEGATE_H_
+#define IOS_CHROME_BROWSER_TABS_TAB_DIALOG_DELEGATE_H_
+
+@class Tab;
+
+// A protocol delegating the display of dialogs for a Tab.
+@protocol TabDialogDelegate
+
+// Displays an HTTP authentication dialog. |completionHandler| should be called
+// with non nil |username| and |password| in order to proceed with
+// authentication.
+- (void)tab:(Tab*)tab
+    runAuthDialogForProtectionSpace:(NSURLProtectionSpace*)protectionSpace
+                 proposedCredential:(NSURLCredential*)credential
+                  completionHandler:
+                      (void (^)(NSString* user, NSString* password))handler;
+
+// Called by Tabs to cancel a previously-requested dialog.
+- (void)cancelDialogForTab:(Tab*)tab;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_TABS_TAB_DIALOG_DELEGATE_H_