Add pixel readback to page popup

Source/core/page/PagePopupDriver.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 11 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef PagePopupDriver_h
 #define PagePopupDriver_h
 
 namespace blink {
 
 class IntRect;
+class LocalDOMWindow;
 class PagePopup;
 class PagePopupClient;
 
 class PagePopupDriver {
 public:
     virtual PagePopup* openPagePopup(PagePopupClient*, const IntRect& originBoundsInRootView) = 0;
     virtual void closePagePopup(PagePopup*) = 0;
+    virtual LocalDOMWindow* pagePopupWindow() = 0;
     virtual ~PagePopupDriver() { }
 };
 
 }
 #endif