Check page URL origin to determine JavaScript alert titles.

ios/chrome/browser/ui/dialogs/dialog_presenter.h

Index: ios/chrome/browser/ui/dialogs/dialog_presenter.h
diff --git a/ios/chrome/browser/ui/dialogs/dialog_presenter.h b/ios/chrome/browser/ui/dialogs/dialog_presenter.h
index 33d38b8c4bfc9ccda6d6928e8d41ff9cc31d20be..50860d517377f189e09927f6c4c42594678bdc57 100644
--- a/ios/chrome/browser/ui/dialogs/dialog_presenter.h
+++ b/ios/chrome/browser/ui/dialogs/dialog_presenter.h
@@ -77,8 +77,11 @@ class WebState;
 // 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