Check page URL origin to determine JavaScript alert titles.

ios/chrome/browser/ui/dialogs/dialog_presenter.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_UI_DIALOGS_DIALOG_PRESENTER_H_
 #define IOS_CHROME_BROWSER_UI_DIALOGS_DIALOG_PRESENTER_H_
 
 #import <UIKit/UIKit.h>
 
 #import "base/ios/block_types.h"
@@ skipping 59 matching lines @@
 - (void)cancelDialogForWebState:(web::WebState*)webState;
 
 // Dismisses the currently presented dialog and cancels all queued dialogs.
 - (void)cancelAllDialogs;
 
 // Tries to present an alert if needed and possible. Called by the view
 // controller which will present the alert to notify that it has dismissed a
 // view controller.
 - (void)tryToPresent;
 
-// Create an title for the alert base on the URL.
-+ (NSString*)localizedTitleForJavaScriptAlertFromPage:(const GURL&)pageURL;
+// Creates a title for the alert base on the URL (|pageURL|), and its
+// relationship to the |mainFrameURL| (typically these are identical except for
+// when posting alerts from an embedded iframe).
++ (NSString*)localizedTitleForJavaScriptAlertFromPage:(const GURL&)pageURL
+                                         mainFrameURL:(const GURL&)mainFrameURL;
 
 @end
 
 @interface DialogPresenter (ExposedForTesting)
 // The dialog currently being shown.
 @property(nonatomic, readonly) AlertCoordinator* presentedDialogCoordinator;
 
 // Called when |coordinator| is stopped.
 - (void)dialogCoordinatorWasStopped:(AlertCoordinator*)coordinator;
 
 @end
 
 // Delegate protocol for DialogPresenter.
 @protocol DialogPresenterDelegate<NSObject>
 
 // Called by |presenter| before showing the queued modal dialog associated with
 // |context|.
 - (void)dialogPresenter:(DialogPresenter*)presenter
     willShowDialogForWebState:(web::WebState*)webState;
 
 // Whether the delegate is presenting another View Controller.
 @property(nonatomic, assign) BOOL presenting;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_DIALOGS_DIALOG_PRESENTER_H_