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

chrome/test/test_browser_window.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_TEST_TEST_BROWSER_WINDOW_H_
 #define CHROME_TEST_TEST_BROWSER_WINDOW_H_
 #pragma once
 
 #include "chrome/browser/browser.h"
 #include "chrome/browser/browser_window.h"
@@ skipping 85 matching lines @@
   virtual void TabContentsFocused(TabContents* tab_contents) {}
   virtual void ShowPageInfo(Profile* profile,
                             const GURL& url,
                             const NavigationEntry::SSLStatus& ssl,
                             bool show_history) {}
   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() { return gfx::Rect(); }
 
  protected:
   virtual void DestroyBrowser() {}
 
  private:
   TestLocationBar location_bar_;
 
   DISALLOW_COPY_AND_ASSIGN(TestBrowserWindow);
 };
 
 #endif  // CHROME_TEST_TEST_BROWSER_WINDOW_H_