Hi Simon,
I cannot find this method in either Node.h or RenderStyle.h.
I wonder that why we cannot get the attribute of an element node just by invoking some member function of the node?

Line 440 of Node.h

virtual RenderStyle* computedStyle();

This gives you renderStyle. If you do position.computedStyle(), you'll obtain CSSComputedStyleDeclaration.

A node could be anything, so you need to first check whether it's an HTML element or not. You can do so by calling node->isElementNode().

Once node->isElementNode() returned, true, you cast the node into Element and call getAttribute there as in:

static_cast<Element*>(node)->getAttribute(qualifiedName)

Please post the questions like this on webkit-help.

Ryosuke