Blink: Pass 'unobscured' rect to WebPlugins.

Source/core/frame/FrameView.h

Index: Source/core/frame/FrameView.h
diff --git a/Source/core/frame/FrameView.h b/Source/core/frame/FrameView.h
index 4056cc832a1a45f5b92b6810bf40a0e9dc0645a1..0796b6bb0513cb592252b51a2749affb2008e094 100644
--- a/Source/core/frame/FrameView.h
+++ b/Source/core/frame/FrameView.h
@@ -154,7 +154,8 @@ public:
 
     void adjustViewSize();
 
-    IntRect windowClipRectForFrameOwner(const HTMLFrameOwnerElement*) const;
+    // |unobscuredRect| receives the clip rect that is not clipped to the root window. It may be nullptr.
+    IntRect clipRectsForFrameOwner(const HTMLFrameOwnerElement*, IntRect* unobscuredRect) const;
 
     float visibleContentScaleFactor() const { return m_visibleContentScaleFactor; }
     void setVisibleContentScaleFactor(float);