Ignore JavaScript messages (alert/confirm/prompt) during unload handlers.

chrome/browser/extensions/extension_host.cc

 // Copyright (c) 2011 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 "chrome/browser/extensions/extension_host.h"
 
 #include <list>
 
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
@@ skipping 411 matching lines @@
         NotificationType::EXTENSION_POPUP_VIEW_READY,
         Source<Profile>(profile_),
         Details<ExtensionHost>(this));
   }
 }
 
 void ExtensionHost::RunJavaScriptMessage(const std::wstring& message,
                                          const std::wstring& default_prompt,
                                          const GURL& frame_url,
                                          const int flags,
+                                         const bool unload_handler_being_run,
                                          IPC::Message* reply_msg,
                                          bool* did_suppress_message) {
   *did_suppress_message = false;
   // Unlike for page alerts, navigations aren't a good signal for when to
   // resume showing alerts, so we can't reasonably stop showing them even if
   // the extension is spammy.
   RunJavascriptMessageBox(profile_, this, frame_url, flags, message,
                           default_prompt, false, reply_msg);
 }
 
@@ skipping 371 matching lines @@
   }
   return window_id;
 }
 
 void ExtensionHost::OnRunFileChooser(
     const ViewHostMsg_RunFileChooser_Params& params) {
   if (file_select_helper_.get() == NULL)
     file_select_helper_.reset(new FileSelectHelper(profile()));
   file_select_helper_->RunFileChooser(render_view_host_, params);
 }