Reset m_didTransformToRootUpdate flag during invalidationTreeIfNeeded

Source/core/rendering/svg/RenderSVGViewportContainer.h

Index: Source/core/rendering/svg/RenderSVGViewportContainer.h
diff --git a/Source/core/rendering/svg/RenderSVGViewportContainer.h b/Source/core/rendering/svg/RenderSVGViewportContainer.h
index f4ce4fea01d7e75898865b2955492ba02bfa73b3..e35e36be6bc13cbcfb350b41aef20e9bf2bcb275 100644
--- a/Source/core/rendering/svg/RenderSVGViewportContainer.h
+++ b/Source/core/rendering/svg/RenderSVGViewportContainer.h
@@ -35,13 +35,15 @@ public:
     FloatRect viewport() const { return m_viewport; }
 
     bool isLayoutSizeChanged() const { return m_isLayoutSizeChanged; }
-    virtual bool didTransformToRootUpdate() OVERRIDE { return m_didTransformToRootUpdate; }
+    virtual bool didTransformToRootUpdate() const OVERRIDE { return m_didTransformToRootUpdate; }
 
     virtual void determineIfLayoutSizeChanged() OVERRIDE;
     virtual void setNeedsTransformUpdate() OVERRIDE { m_needsTransformUpdate = true; }
 
     virtual void paint(PaintInfo&, const LayoutPoint&) OVERRIDE;
 
+    virtual void clearPaintInvalidationState() OVERRIDE;

[Julien - ping for review, 2014/07/23 18:47:39]

This should be private as we assume people will call the RenderObject one.

[Xianzhu, 2014/07/23 19:05:08]

Done.

+
 private:
     virtual bool isSVGViewportContainer() const OVERRIDE { return true; }
     virtual const char* renderName() const OVERRIDE { return "RenderSVGViewportContainer"; }
@@ -55,6 +57,10 @@ private:
     virtual void applyViewportClip(PaintInfo&) OVERRIDE;
     virtual bool pointIsInsideViewportClip(const FloatPoint& pointInParent) OVERRIDE;
 
+#if ENABLE(ASSERT)
+    virtual bool paintInvalidationStateIsDirty() const OVERRIDE  { return RenderSVGContainer::paintInvalidationStateIsDirty() || m_didTransformToRootUpdate; }
+#endif
+
     FloatRect m_viewport;
     mutable AffineTransform m_localToParentTransform;
     bool m_didTransformToRootUpdate : 1;