Remove the ability of webpages to specify strings for the onbeforeunload dialog.

third_party/WebKit/Source/core/page/ChromeClient.cpp

 /*
  * Copyright (C) 2006, 2007, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2012, Samsung Electronics. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 75 matching lines @@
 
     InspectorInstrumentationCookie cookie = InspectorInstrumentation::willRunJavaScriptDialog(frame, message, dialogType);
     bool result = delegate();
     InspectorInstrumentation::didRunJavaScriptDialog(cookie, result);
     return result;
 }
 
 bool ChromeClient::openBeforeUnloadConfirmPanel(const String& message, LocalFrame* frame, bool isReload)
 {
     ASSERT(frame);
-    return openJavaScriptDialog(frame, message, ChromeClient::HTMLDialog, [this, frame, &message, isReload]() {
-        return openBeforeUnloadConfirmPanelDelegate(frame, message, isReload);
+    return openJavaScriptDialog(frame, message, ChromeClient::HTMLDialog, [this, frame, isReload]() {
+        return openBeforeUnloadConfirmPanelDelegate(frame, isReload);
     });
 }
 
 bool ChromeClient::openJavaScriptAlert(LocalFrame* frame, const String& message)
 {
     ASSERT(frame);
     if (!canOpenModalIfDuringPageDismissal(frame->tree().top(), ChromeClient::AlertDialog, message))
         return false;
     return openJavaScriptDialog(frame, message, ChromeClient::AlertDialog, [this, frame, &message]() {
         return openJavaScriptAlertDelegate(frame, message);
@@ skipping 76 matching lines @@
 {
     // Defer loads in case the client method runs a new event loop that would
     // otherwise cause the load to continue while we're in the middle of
     // executing JavaScript.
     ScopedPageLoadDeferrer deferrer;
 
     printDelegate(frame);
 }
 
 } // namespace blink