Makes instant run before unload listeners.

chrome/browser/instant/instant_unload_handler.h

+// Copyright (c) 2010 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_INSTANT_INSTANT_UNLOAD_HANDLER_H_
+#define CHROME_BROWSER_INSTANT_INSTANT_UNLOAD_HANDLER_H_
+#pragma once
+
+#include "base/scoped_vector.h"
+
+class Browser;
+class TabContentsWrapper;
+
+// InstantUnloadHandler makes sure the before unload and unloader handler is run

[Charlie Reis, 2010/12/08 05:50:11]

nit: unloader -> unload

This comment is much better, thanks.

+// when using instant. When the user commits the instant preview the existing
+// TabContentsWrapper is passed to |Own|. If the tab has no before unload or
+// unload listener the tab is deleted, otherwise the before unload and unload
+// listener is executed. If the before unload listener shows a dialog the tab is
+// added back to the tabstrip at its original location next to the instant page.
+class InstantUnloadHandler {
+ public:
+  explicit InstantUnloadHandler(Browser* browser);
+  ~InstantUnloadHandler();
+
+  // See class description for details on what this does.
+  void Own(TabContentsWrapper* tab_contents, int index);
+
+ private:
+  class TabContentsDelegateImpl;
+
+  // Invoked if the tab is to be shown. This happens if the before unload
+  // listener returns a string.
+  void Activate(TabContentsDelegateImpl* delegate);
+
+  // Destroys the old tab. This is invoked if script tries to close the page.
+  void Destroy(TabContentsDelegateImpl* delegate);
+
+  // TODO(sky): browser really needs to wait to close until there are no more
+  // tabs managed by InstantUnloadHandler.
+  Browser* browser_;
+
+  ScopedVector<TabContentsDelegateImpl> delegates_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstantUnloadHandler);
+};
+
+#endif  // CHROME_BROWSER_INSTANT_INSTANT_UNLOAD_HANDLER_H_