We have a problem in the process on destroying WebContentsImpl because

chrome/browser/apps/ephemeral_app_launcher.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 "chrome/browser/apps/ephemeral_app_launcher.h"
 
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 234 matching lines @@
 
   // If the installation succeeds, we reach this point as a result of
   // chrome::NOTIFICATION_EXTENSION_INSTALLED, but this is broadcasted before
   // ExtensionService has added the extension to its list of installed
   // extensions and is too early to launch the app. Instead, we will launch at
   // EphemeralAppLauncher::OnExtensionLoaded().
   // TODO(tmdiep): Refactor extensions/WebstoreInstaller or
   // WebstoreStandaloneInstaller to support this cleanly.
 }
 
-void EphemeralAppLauncher::WebContentsDestroyed(
-    content::WebContents* web_contents) {
+void EphemeralAppLauncher::WebContentsDestroyed() {
   AbortInstall();
 }
 
 void EphemeralAppLauncher::OnExtensionLoaded(
     content::BrowserContext* browser_context,
     const Extension* extension) {
   if (extension->id() == id()) {
     LaunchApp(extension);
     WebstoreStandaloneInstaller::CompleteInstall(std::string());
   }
 }
 
 void EphemeralAppLauncher::ExtensionEnableFlowFinished() {
   ExtensionService* extension_service =
       extensions::ExtensionSystem::Get(profile())->extension_service();
   DCHECK(extension_service);
 
   const Extension* extension = extension_service->GetExtensionById(id(), false);
   if (extension) {
     LaunchApp(extension);
     WebstoreStandaloneInstaller::CompleteInstall(std::string());
   } else {
     WebstoreStandaloneInstaller::CompleteInstall(kLaunchAbortedError);
   }
 }
 
 void EphemeralAppLauncher::ExtensionEnableFlowAborted(bool user_initiated) {
   WebstoreStandaloneInstaller::CompleteInstall(kLaunchAbortedError);
 }