Makes the current page dim out when transitioning to instant preview.

chrome/browser/cocoa/browser_window_cocoa.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_COCOA_BROWSER_WINDOW_COCOA_H_
 #define CHROME_BROWSER_COCOA_BROWSER_WINDOW_COCOA_H_
 #pragma once
 
 #include "base/scoped_nsobject.h"
 #include "base/task.h"
@@ skipping 89 matching lines @@
   virtual void ShowAppMenu();
   virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
                                       bool* is_keyboard_shortcut);
   virtual void HandleKeyboardEvent(const NativeWebKeyboardEvent& event);
   virtual void ShowCreateShortcutsDialog(TabContents* tab_contents);
   virtual void Cut();
   virtual void Copy();
   virtual void Paste();
   virtual void ToggleTabStripMode();
   virtual void OpenTabpose();
+  virtual void PrepareForInstant();
   virtual void ShowInstant(TabContents* preview_contents);
   virtual void HideInstant();
   virtual gfx::Rect GetInstantBounds();
 
   // Overridden from NotificationObserver
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
   // Adds the given FindBar cocoa controller to this browser window.
@@ skipping 12 matching lines @@
   void UpdateSidebarForContents(TabContents* tab_contents);
 
   NotificationRegistrar registrar_;
   Browser* browser_;  // weak, owned by controller
   BrowserWindowController* controller_;  // weak, owns us
   ScopedRunnableMethodFactory<Browser> confirm_close_factory_;
   scoped_nsobject<NSString> pending_window_title_;
 };
 
 #endif  // CHROME_BROWSER_COCOA_BROWSER_WINDOW_COCOA_H_