This is a follow-up for bug 257822. Setting a state on the RenderStyle to fix the blend mode bug 225446 was not the right approach. Instead we should add the flag PaintBehavior::DontShowVisitedLinks if the blendMode() is not equal to BlendMode::Normal.
<rdar://problem/114277041>
I think this bug is invalid. Having the blendMode() of an element not equal to BlendMode::Normal should affect that element and all its descents. And this is why we set the blendMode in m_nonInheritedData but we set isInSubtreeWithBlendMode in m_rareInheritedData. So there will be no easy way to check the blendMode() of the parent elements all the way up till the root and check any of them is not equal to BlendMode::Normal to add PaintBehavior::DontShowVisitedLinks to the drawing paintBehavior in this case.