Fix crash when an extension popup shows a JS alert. Showing the alert takes...

chrome/browser/extensions/extension_host.h

 // Copyright (c) 2006-2009 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_HOST_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_HOST_H_
 
 #include <string>
 
 #include "base/perftimer.h"
@@ skipping 138 matching lines @@
 
   // JavaScriptMessageBoxClient
   virtual std::wstring GetMessageBoxTitle(const GURL& frame_url,
                                           bool is_alert);
   virtual gfx::NativeWindow GetMessageBoxRootWindow();
   virtual void OnMessageBoxClosed(IPC::Message* reply_msg,
                                   bool success,
                                   const std::wstring& prompt);
   virtual void SetSuppressMessageBoxes(bool suppress_message_boxes) {}
   virtual TabContents* AsTabContents() { return NULL; }
+  virtual ExtensionHost* AsExtensionHost() { return this; }
 
  private:
   friend class ProcessCreationQueue;
 
   // Whether to allow DOM automation for created RenderViewHosts. This is used
   // for testing.
   static bool enable_dom_automation_;
 
   // Actually create the RenderView for this host. See CreateRenderViewSoon.
   void CreateRenderViewNow();
@@ skipping 50 matching lines @@
   // are used here, others are not hosted by ExtensionHost.
   ViewType::Type extension_host_type_;
 
   // Used to measure how long it's been since the host was created.
   PerfTimer since_created_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionHost);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_HOST_H_