Refactor RenderBox::addVisualEffectOverflow()

Source/core/rendering/RenderBox.h

Index: Source/core/rendering/RenderBox.h
diff --git a/Source/core/rendering/RenderBox.h b/Source/core/rendering/RenderBox.h
index f0af62a93a0a9fd9c19aa6b252f9246fb33a48e9..1db90db31a2d585d4acbdc8a54e7b71912a3b72f 100644
--- a/Source/core/rendering/RenderBox.h
+++ b/Source/core/rendering/RenderBox.h
@@ -225,7 +225,9 @@ public:
     // Clipped by the contents clip, if one exists.
     void addContentsVisualOverflow(const LayoutRect&);
 
+    bool hasVisualEffectOverflow() const { return style()->boxShadow() || style()->hasBorderImageOutsets() || style()->hasOutline(); }

[Julien - ping for review, 2014/07/01 23:00:16]

https://codereview.chromium.org/204843002 landed which adds this function to
RenderStyle (where it belongs) so you will need to rebaseline the change.

[Xianzhu, 2014/07/02 00:02:03]

Done.

     void addVisualEffectOverflow();
+    LayoutBoxExtent computeVisualEffectOverflowExtent() const;
     void addOverflowFromChild(RenderBox* child) { addOverflowFromChild(child, child->locationOffset()); }
     void addOverflowFromChild(RenderBox* child, const LayoutSize& delta);
     void clearLayoutOverflow();