Move Sad Tab implementation out of the TabContentsViews.

chrome/browser/ui/sad_tab_observer.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_SAD_TAB_OBSERVER_H_
+#define CHROME_BROWSER_UI_SAD_TAB_OBSERVER_H_
+#pragma once
+
+#include "base/memory/scoped_ptr.h"
+#include "content/browser/tab_contents/tab_contents_observer.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#include "ui/gfx/native_widget_types.h"
+
+#if defined(OS_MACOSX)
+#include "base/mac/foundation_util.h"
+#endif
+
+#if defined(OS_MACOSX)
+class SadTabController;
+#elif defined(TOOLKIT_VIEWS)
+namespace views {
+class Widget;
+}
+#elif defined(TOOLKIT_GTK)
+class SadTabGtk;
+#endif
+
+// Per-tab class to manage sad tab views.
+class SadTabObserver : public TabContentsObserver,
+                       public content::NotificationObserver {
+ public:
+  explicit SadTabObserver(TabContents* tab_contents);
+  virtual ~SadTabObserver();
+
+ private:
+  // Platform specific function to get an instance of the sad tab page.
+  gfx::NativeView AcquireSadTab(base::TerminationStatus status);
+
+  // Platform specific function to release the instance of the sad tab page.
+  void ReleaseSadTab();
+
+  // Platform specific function to determine if there is a current sad tab page.
+  bool HasSadTab();
+
+  // Overridden from TabContentsObserver:
+  virtual void RenderViewGone(base::TerminationStatus status) OVERRIDE;
+
+  // Overridden from content::NotificationObserver:
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  // Used to get notifications about renderers coming and going.
+  content::NotificationRegistrar registrar_;
+
+  // The platform views used to render the sad tab, non-NULL if visible.
+#if defined(OS_MACOSX)
+  class ScopedPtrRelease {
+   public:
+    inline void operator()(void* x) const {
+      base::mac::NSObjectRelease(x);
+    }
+  };
+  scoped_ptr_malloc<SadTabController, ScopedPtrRelease> sad_tab_;
+#elif defined(TOOLKIT_VIEWS)
+  scoped_ptr<views::Widget> sad_tab_;
+#elif defined(TOOLKIT_GTK)
+  scoped_ptr<SadTabGtk> sad_tab_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(SadTabObserver);
+};
+
+#endif  // CHROME_BROWSER_UI_SAD_TAB_OBSERVER_H_