Blink: Pass 'unobscured' rect to WebPlugins.

Source/core/frame/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
@@ skipping 138 matching lines @@
     bool hasOpaqueBackground() const;
 
     Color baseBackgroundColor() const;
     void setBaseBackgroundColor(const Color&);
     void updateBackgroundRecursively(const Color&, bool);
 
     void adjustViewSize();
 
     IntRect windowClipRectForFrameOwner(const HTMLFrameOwnerElement*) const;
 
+    // Returns the clip rect for the element without clipping to the root view.
+    // Used to determine the visible portion of elements below the fold.
+    IntRect unobscuredRectForFrameOwner(const HTMLFrameOwnerElement*) const;
+
     float visibleContentScaleFactor() const { return m_visibleContentScaleFactor; }
     void setVisibleContentScaleFactor(float);
 
     // Scale used to convert incoming input events. Usually the same as visibleContentScaleFactor(), unless specifically changed.
     float inputEventsScaleFactor() const;
     // Offset used to convert incoming input events while emulating device metics.
     IntSize inputEventsOffsetForEmulation() const;
     void setInputEventsTransformForEmulation(const IntSize&, float);
 
     virtual void setScrollPosition(const DoublePoint&, ScrollBehavior = ScrollBehaviorInstant) override;
@@ skipping 702 matching lines @@
     static const unsigned visualPixelThreshold = 32 * 32;
     if (m_visuallyNonEmptyPixelCount > visualPixelThreshold)
         setIsVisuallyNonEmpty();
 }
 
 DEFINE_TYPE_CASTS(FrameView, Widget, widget, widget->isFrameView(), widget.isFrameView());
 
 } // namespace blink
 
 #endif // FrameView_h