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

android_webview/browser/aw_javascript_dialog_manager.cc

 // Copyright (c) 2012 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.
 
 #include "android_webview/browser/aw_javascript_dialog_manager.h"
 
 #include "android_webview/browser/aw_contents_client_bridge_base.h"
 #include "content/public/browser/javascript_dialog_manager.h"
 #include "content/public/browser/web_contents.h"
 
@@ skipping 21 matching lines @@
 
   bridge->RunJavaScriptDialog(message_type,
                               origin_url,
                               message_text,
                               default_prompt_text,
                               callback);
 }
 
 void AwJavaScriptDialogManager::RunBeforeUnloadDialog(
     content::WebContents* web_contents,
-    const base::string16& message_text,
     bool is_reload,
     const DialogClosedCallback& callback) {
   AwContentsClientBridgeBase* bridge =
       AwContentsClientBridgeBase::FromWebContents(web_contents);
   if (!bridge) {
     callback.Run(false, base::string16());
     return;
   }
 
   bridge->RunBeforeUnloadDialog(web_contents->GetURL(),
-                                message_text,
                                 callback);
 }
 
 void AwJavaScriptDialogManager::CancelActiveAndPendingDialogs(
     content::WebContents* web_contents) {
 }
 
 void AwJavaScriptDialogManager::ResetDialogState(
     content::WebContents* web_contents) {
 }
 
 }  // namespace android_webview