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

content/browser/web_contents/web_contents_impl.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 "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 3860 matching lines @@
                    render_frame_host->GetRoutingID(), reply_msg,
                    true, false, base::string16());
   }
 
   // OnDialogClosed (two lines up) may have caused deletion of this object (see
   // http://crbug.com/288961 ). The only safe thing to do here is return.
 }
 
 void WebContentsImpl::RunBeforeUnloadConfirm(
     RenderFrameHost* render_frame_host,
-    const base::string16& message,
     bool is_reload,
     IPC::Message* reply_msg) {
   RenderFrameHostImpl* rfhi =
       static_cast<RenderFrameHostImpl*>(render_frame_host);
   if (delegate_)
     delegate_->WillRunBeforeUnloadConfirm();
 
   bool suppress_this_message =
       rfhi->rfh_state() != RenderFrameHostImpl::STATE_DEFAULT ||
       ShowingInterstitialPage() || !delegate_ ||
       delegate_->ShouldSuppressDialogs(this) ||
       !delegate_->GetJavaScriptDialogManager(this);
   if (suppress_this_message) {
     rfhi->JavaScriptDialogClosed(reply_msg, true, base::string16(), true);
     return;
   }
 
   is_showing_before_unload_dialog_ = true;
   dialog_manager_ = delegate_->GetJavaScriptDialogManager(this);
   dialog_manager_->RunBeforeUnloadDialog(
-      this, message, is_reload,
+      this, is_reload,
       base::Bind(&WebContentsImpl::OnDialogClosed, base::Unretained(this),
                  render_frame_host->GetProcess()->GetID(),
                  render_frame_host->GetRoutingID(), reply_msg,
                  false));
 }
 
 WebContents* WebContentsImpl::GetAsWebContents() {
   return this;
 }
 
@@ skipping 941 matching lines @@
   else
     WasHidden();
 }
 
 void WebContentsImpl::SetJavaScriptDialogManagerForTesting(
     JavaScriptDialogManager* dialog_manager) {
   dialog_manager_ = dialog_manager;
 }
 
 }  // namespace content