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

content/shell/browser/shell_javascript_dialog_manager.cc

 // Copyright 2013 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 "content/shell/browser/shell_javascript_dialog_manager.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
@@ skipping 48 matching lines @@
                                           callback));
 #else
   // TODO: implement ShellJavaScriptDialog for other platforms, drop this #if
   *did_suppress_message = true;
   return;
 #endif
 }
 
 void ShellJavaScriptDialogManager::RunBeforeUnloadDialog(
     WebContents* web_contents,
-    const base::string16& message_text,
     bool is_reload,
     const DialogClosedCallback& callback) {
   if (!dialog_request_callback_.is_null()) {
     dialog_request_callback_.Run();
     callback.Run(true, base::string16());
     dialog_request_callback_.Reset();
     return;
   }
 
 #if defined(OS_MACOSX) || defined(OS_WIN)
   if (dialog_) {
     // Seriously!?
     callback.Run(true, base::string16());
     return;
   }
 
-  base::string16 new_message_text =
-      message_text +
-      base::ASCIIToUTF16("\n\nIs it OK to leave/reload this page?");
+  base::string16 message_text =
+      base::ASCIIToUTF16("Is it OK to leave/reload this page?");
 
   gfx::NativeWindow parent_window = web_contents->GetTopLevelNativeWindow();
 
   dialog_.reset(new ShellJavaScriptDialog(this,
                                           parent_window,
                                           JAVASCRIPT_MESSAGE_TYPE_CONFIRM,
-                                          new_message_text,
+                                          message_text,
                                           base::string16(),  // default
                                           callback));
 #else
   // TODO: implement ShellJavaScriptDialog for other platforms, drop this #if
   callback.Run(true, base::string16());
   return;
 #endif
 }
 
 void ShellJavaScriptDialogManager::CancelActiveAndPendingDialogs(
@@ skipping 14 matching lines @@
 void ShellJavaScriptDialogManager::DialogClosed(ShellJavaScriptDialog* dialog) {
 #if defined(OS_MACOSX) || defined(OS_WIN)
   DCHECK_EQ(dialog, dialog_.get());
   dialog_.reset();
 #else
   // TODO: implement ShellJavaScriptDialog for other platforms, drop this #if
 #endif
 }
 
 }  // namespace content