We have a problem in the process on destroying WebContentsImpl because

content/shell/browser/shell_devtools_frontend.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_devtools_frontend.h"
 
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 109 matching lines @@
   DevToolsManager* manager = DevToolsManager::GetInstance();
   manager->RegisterDevToolsClientHostFor(agent_host_.get(),
                                          frontend_host_.get());
 }
 
 void ShellDevToolsFrontend::DocumentOnLoadCompletedInMainFrame(int32 page_id) {
   web_contents()->GetMainFrame()->ExecuteJavaScript(
       base::ASCIIToUTF16("InspectorFrontendAPI.setUseSoftMenu(true);"));
 }
 
-void ShellDevToolsFrontend::WebContentsDestroyed(WebContents* web_contents) {
+void ShellDevToolsFrontend::WebContentsDestroyed() {
   DevToolsManager::GetInstance()->ClientHostClosing(frontend_host_.get());
   delete this;
 }
 
 void ShellDevToolsFrontend::InspectedContentsClosing() {
   frontend_shell_->Close();
 }
 
 }  // namespace content