showNodePath will be useful for debugging purpose.

showNodePath will be useful for debugging purpose.
https://bugs.webkit.org/show_bug.cgi?id=86450

This patch implements showNodePath, which outputs node information in
a xpath-like format, e.g. /HTML/BODY/DIV[@id="test" and position()=0]/P[0]

Patch by Takashi Sakamoto <tasak@google.com> on 2012-05-17
Reviewed by Hajime Morita.

No new tests, just adding debugging interface.

* dom/Node.cpp:
(WebCore::Node::showNodePathForThis):
(WebCore):
(showNodePath):
* dom/Node.h:
(Node):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@117417 268f45cc-cd09-0410-ab3c-d52691b4dbfc